%0 Conference Paper %B 2020 SAWE Tech Fair %D 2020 %T 3752. A Portable Device for Measuring the Cog: Design, Error Analysis and Calibration %A Giorgio Previati %A Ballo, Federico %A Gobbi, Massimiliano %K 03. Center Of Gravity %K 09. Weighing Equipment %X

The paper is devoted to the design, error estimation and calibration of a portable device for the measurement of the centre of gravity of rigid bodies. The device consists in a simple but effective implementation of the knife edge method. The design of the device including safety considerations is fully described. An error estimation approach is employed in the very early stage of the design to assess the required instrumentation accuracy and the manufacturing tolerances. A calibration of the portable device is performed by means of proper calibrated masses. After calibration, the accuracy of the device corresponds to the target accuracy defined in the a-priori error analysis.

The design procedure described in the paper shows a straightforward approach for the design of devices for the measurement of the inertia properties. By such a procedure, it is possible to identify the most critical design areas and make the correct choices in the early stage of the design process. Also, a deep understanding of the measuring process can be gained allowing the definition of an effective calibration procedure.

%B 2020 SAWE Tech Fair %I Society of Allied Weight Engineers, Inc. %C Virtual Conference %P 18 %8 07/2020 %U https://www.sawe.org/papers/3752/buy %L 3, 9 %1

Non-Member Price: $20.00; Member Price: $15.00

%2 15 %3 20 %4 SAWE3730 %0 Conference Paper %B 2020 SAWE Tech Fair %D 2020 %T 3753. Theoretical and Experimental Evaluation of the Flexibility of the Test Rig on Inertia Property Measurement %A Giorgio Previati %A Mastinu, Gianpiero %A Gobbi, Massimiliano %K 06. Inertia Measurements %K 09. Weighing Equipment %X

In the measurement of inertia properties (mass, centre of gravity and inertia tensor), both the body under investigation and the test rig are commonly considered as rigid bodies. However, in case of heavy or large bodies, these assumptions may not be satisfied. The present paper deals with the consequences of the test rig structure deformations on the measured inertia parameters. In fact, if the forces exchanged by the structure of the test rig and the body are large, the structure may deform changing its geometry and dynamic behavior. These effects, in turn, affect the measured kinematic and dynamic quantities needed for the measurement of the inertia properties.

In the paper, by considering the InTenso+ Measuring System of the Politecnico di Milano, a special type of multi-filar pendulum, the effects of the deformation of the test rig on the measurement of the inertia properties is investigated both numerically and experimentally. A flexible multibody model is employed to understand the dynamic effects of the deformations on the mass properties measurement. Several bodies are measured to validate such analyses. A proper mathematical procedure is then derived to measure the inertia properties of bodies when the realization of a sufficiently stiff structure is impractical.

%B 2020 SAWE Tech Fair %I Society of Allied Weight Engineers, Inc. %C Virtual Conference %P 14 %8 07/2020 %U https://www.sawe.org/papers/3753/buy %L 6, 9 %1

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%2 15 %3 20 %4 SAWE3730 %0 Conference Paper %B 78th Annual Conference, Norfolk, VA %D 2019 %T 3721. A Weight and Center of Gravity Instrument for Measuring Manned Spacecraft %A Otlowski, Dan %K 09. Weighing Equipment %X

Rocketry dynamics equations prescribe that the mass properties of spacecraft, particularly the spacecraft’s mass and center of gravity (CG), be carefully choreographed throughout the launch, mission execution, and recovery stages. Mission design carefully selects CG locations for each of the spacecraft modules alone and in combinations, making CG verification an important step toward ensuring mission success. Measuring the CG of large spacecraft presents many of the typical problems associated with measuring CG of smaller objects. Some of these issues are commonly: constructing a measuring system with known geometry, maintaining the repeatability of said geometry under a wide array of load conditions, selecting force transducers with sensitivity appropriate to the verification tolerance, preserving that sensitivity throughout the measurement, and devising a method to relate the spacecraft’s datum to the instrument’s datum. A purpose-built, mass properties measurement solution that addresses all of these issues is the topic of this paper. In this paper, we will describe the form of the instrument, detail enabling technologies, explain performance drivers, and summarize our results.

%B 78th Annual Conference, Norfolk, VA %I Society of Allied Weight Engineers, Inc. %C Norfolk, Virginia %P 23 %8 05/2019 %U https://www.sawe.org/papers/3721/buy %L 9 %1 Non-Member Price: $20.00; Member Price: $15.00 %2 15 %3 20 %4 SAWE3721 %0 Conference Paper %B 77th Annual Conference, Irving, Texas %D 2018 %T 3696. A Novel Approach for an Autonomous Weighing System through Fuselage Interface Loads %A Shachar, Oran %K 09. Weighing Equipment %X

According to a N.A.L report, from May 2007 (G.W.H.van Es[ 4]), each year numerous aircraft accidents occur due to weight and balance issues, major factors in weight and balance accidents/incidents being errors in load sheet, cargo shifting, incorrect loading etc. This paper presents an ESL patented novel method and system for estimating an aircraft’s weight while it is on the ground. Additionally, the system enables measuring the takeoff/landing weight profile, which includes information pertaining to weight/force as a function of time, including the time of contact with the ground. This enables various conditions such as heavy landing and the like to be identified.

One of the main advantages of this development, over prior methods, is that this system measures loads above the landing gear, thus avoiding bias due to the flexibility of the landing gears. It also offers high repeatability of the measured load.

The measurement subsystem includes sensors configured to measure a physical property (load/strain) at several locations near and/or at the fuselage interface with the landing gears. Such a sensor can be based on several technologies such as: strain gages, optical fibers (Bragg Gratings), load cells, etc.

The specific solution and sensor implemented is a tailor-made design for each aircraft, taking into account the effect of the aircraft weight and desired sensitivity due to weight change on the results being measured.

As part of the work done by ESL in developing the system, that for a given (existing) Hermes 900 fleet, an average of 1 flight hour can be saved.
This paper presents the design and integration of such a system on ESL’s Hermes 450 UAV, based on load cells. A proof-of-concept test was performed and is presented in this paper.

The main test findings show, that the maximum deviation between the standard weighing procedure and ESL’s system result is 0.6% at weight and 0.9% at COG.

The conceptual methodology suggested here is still under development. Nevertheless, the integration of the sensor technology into the fuselage has its own promise to develop higher levels of safety of flight, while increasing the specific range of the aircraft.

%B 77th Annual Conference, Irving, Texas %I Society of Allied Weight Engineers, Inc. %C Irving, Texas %P 27 %8 05/2018 %U https://www.sawe.org/papers/3696/buy %1 Non-Member Price: $20.00; Member Price: $15.00 Members: First 10 product downloads are Free. %2 15 %3 20 %4 SAWE3696 %0 Conference Paper %B 67th Annual Conference, Seattle, Washington %D 2008 %T 3436. Instant CG %A Kalaghatagi, Amith %K 03. Center Of Gravity %K 09. Weighing Equipment %X This paper describes in detail a method to measure the CG of any aircraft at any pitch angle, without having to adjust the aircraft to flight level conditions. This method reduces the time required for weighing, eliminates human error, and eliminates possibility of aircraft damage due to jacking accidents and possibility of injury to weighing personnel. This method is applicable to all aircraft types and configurations. A system of linear equations is solved to compute the CG of the aircraft. The known variables in the system of equations are the pitch angle, oleo extensions and the wheel reactions. The unknowns in the system are the Weight, Arm lengths and CG. The first equation of the system consists of the Moment of all forces computed about the Reference Datum. The remaining equations consist of the functions defining the relation between Arm lengths with respect to the Reference Datum for each wheel and the Oleo extensions of the respective wheels. The pitch angle is measured accurately within one-tenths of a degree, the oleo extensions are measured accurately within one-hundredths of an inch and the wheel reactions within one pound. For each aircraft configuration, we use a GEC custom complex algorithm to compute the arm lengths from the measured oleo extensions. Once the aircraft is rolled onto the GEC platform scales, the reactions are wirelessly transmitted to the GEC handheld equipment through RF. The pitch angle and the oleo extensions are measured and manually entered into the GEC handheld. With these input variables the CG, %MAC and Total Weight of the aircraft are instantaneously computed by the GEC handheld equipment. A test aircraft was weighed both level and off-level to test the algorithm. The computed CG was within 0.1 inches and the %MAC was within 0.1%. %B 67th Annual Conference, Seattle, Washington %C Seattle, Washington %P 16 %8 5/19/2008 %U https://www.sawe.org/papers/3436/buy %9 3. CENTER OF GRAVITY;9. WEIGHING EQUIPMENT %M 3436 %L 3;9 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE3436 %0 Conference Paper %B 66th Annual Conference, Madrid, Spain %D 2007 %T 3402. Ship Inclining Experiment Accessory Kit %A Schuster, Andreas %A Oole, Thomas %A Fox, William %K 09. Weighing Equipment %K 13. Weight Engineering - Marine %K 35. Weight Engineering - Offshore %X US Military aircraft weighing standards specify the use of an accessory kit that includes tools similar to those used by weight engineers and naval architects for ship inclining experiments. The procurement of ship inclining experiment tools and accessories is currently a rather tedious, word of mouth process. This paper describes the typical contents of an aircraft weighing accessory kit. It then describes the ship inclining experiment and lists the tools used during the inclining process. From this, a specification and list for a ship inclining accessory kit is proposed. Hopefully, this paper will provide insight to equipment suppliers to enable them to create a Ship Inclining Experiment Accessory Kit for the marine industry. %B 66th Annual Conference, Madrid, Spain %I Society of Allied Weight Engineers %C Madrid, Spain %P 15 %8 5/28/2007 %G eng %U https://www.sawe.org/papers/3402/buy %9 9. WEIGHING EQUIPMENT; 13. WEIGHT ENGINEERING - MARINE %M 3402 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE3402 %0 Conference Paper %B 65th Annual Conference, Valencia, California %D 2006 %T 3384. Measuring Weight And Center Of Gravity Using Load Cells %A Hill, Brad %K 08. Weighing %K 09. Weighing Equipment %K Mike Hackney Best Paper Award %X

Today?s load cells are capable of an accuracy of +-0.05%, or better, under ideal conditions. But ideal conditions are expensive to obtain and, because ?you get what you pay for,? these high accuracies are not always possible or even required. Given sufficient time and money most anything can be weighed to a high degree of accuracy. More often we are asked to measure the weight and center of gravity of an object when the design and building of specialized fixtures and laboratory conditions is not practical or warranted. To meet the needs of a customer without exceeding his budget we are often required to be creative in how we use the equipment available while keeping in mind the accuracy and validity of the data we are gathering. Many things will affect the accuracy of the information we get from a test, especially the quality of the equipment, the physical arrangement, our procedures and the calibration uncertainty of the load cells. There are just as many areas where confidence can be built into a test. To obtain the best value for the dollar from our test we must consider things like the set-up of the test, weight and dimensional measurements, environmental factors and equipment shortcomings. For the purpose of this paper the term ?load cell? refers to stand alone canister-type cells, like those in a standard aircraft weighing kit, that are not part of a permanent fixture. This type of equipment is commonly used to measure the weight and center of gravity of large parts, assemblies, tooling, missiles and other items where a unique set-up is required for each.

%B 65th Annual Conference, Valencia, California %I Society of Allied Weight Engineers %C Valencia, California %P 19 %8 5/20/2006 %G eng %U https://www.sawe.org/papers/3384/buy %9 8. WEIGHING; 9. WEIGHING EQUIPMENT %M 3384 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE3384 %0 Conference Paper %B 60th Annual Conference, Arlington, Texas, May 19-23 %D 2001 %T 3150. Wireless Weighing %A Lindberg, George %K 09. Weighing Equipment %X Portable weighing systems have been available for many years for weighing aircraft or ground vehicles. These systems traditionally used remote weighing sensors connected through a web of cables to a remote sensing or display instrument. These systems used the analog outputs of the sensing elements transmitted through cables to a single a/d converter mounted in the remote instrument. This left a lot to be desired in as much as the low level analog signals were effected by changes in temperature or resistance in the wiring due to crimps or crushing of the cabling. The load sensing devices were highly affected by false loads introduced by the canted landing gear or off level weighing services. Leveling of the platforms or load cells to accommodate the off level conditions of hangar floors or weighing areas was always a concern and in all cases a necessity. Many systems still have "sweet spots" or weighing areas marked on the platform. In the late 1980's, GEC introduced and patented the first platform and load cell sensing devices with a self-contained a/d converter, self leveling, or side load canceling capabilities, power supply, digital display and remote indicating device. Finally, a weighing system without cables for either power or indication! However, the many advances made by GEC, still did not solve all of the portable weighing problems associated with using a plurality of sensing devices, especially when multiple sensors were needed in order to accurately weigh the vehicle. GEC then designed and patented a method of connecting via cables multiple sending devices to a remote computer in order to get real time weights and C. G. In fact, GEC manufactured a system for McDonnell Douglas for weighing and dispatching the MD-11 and C-17 in adverse flight test situations. In 1992, GEC introduced and patented the first ever remote transmission capabilities without the use of connecting cables. However, at the time GEC was so far ahead of technology that the systems proved to be very expensive due to the cost of the transmission equipment. Technology and production has finally caught up to GEC and the products introduced then are now affordable. %B 60th Annual Conference, Arlington, Texas, May 19-23 %I Society of Allied Weight Engineers, Inc. %C Arlington, Texas %P 7 %8 5/19/01 %G eng %U https://www.sawe.org/papers/3150/buy %9 9. WEIGHING EQUIPMENT %M 3150 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE3150 %0 Conference Paper %B 60th Annual Conference, Arlington, Texas, May 19-23 %D 2001 %T 3160. Dynamic On-Board Weight and Balance System for Aircraft %A Von Bose, Robert %K 09. Weighing Equipment %X There is an increasing awareness among aircraft operators that an on-board weight and balance system is not only a safety measure but also a tool to enhance profits in two important ways. First, with a reliable measurement of actual weight the operator can confidently approach the maximum gross take-off weight of the aircraft and also accumulate records for loading and operational efficiency studies. This means bigger payloads with peace of mind. Second, by using the system at selected intervals during loading, the payload yet to be loaded may be located to trim the aircraft for optimum fuel efficiency. The system must be an integral part of the aircraft and derive accurate aircraft weight and location of the center of gravity, while resting on any reasonable level surface, within a very short time. The potential users of such systems want answers to several questions. How reliable is the system? How accurate is the information? What is the weight penalty for installation? Does it increase or decrease our gate time? Is it user-friendly? And, what does it cost? To the design engineer this means a fast, reliable, easy-to-use system in which every source of error has been minimized to the extent possible within state-of-the-art and economic limits. "Economic Limits" means designing so the manufacturer can produce and sell it at a price the user considers "cost effective." %B 60th Annual Conference, Arlington, Texas, May 19-23 %I Society of Allied Weight Engineers, Inc. %C Arlington, Texas %P 5 %8 5/19/01 %G eng %U https://www.sawe.org/papers/3160/buy %9 9. WEIGHING EQUIPMENT %M 3160 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE3160 %0 Conference Paper %B 59th Annual Conference, St. Louis, Missouri, June 5-7 %D 2000 %T 3021. Fundamentals of Electronic Weighing Systems %A Turner, Bill %K 09. Weighing Equipment %X Fundamentals of Electronic Weighing Systems guides readers through every facet of the weighing system design, implementation, and troubleshooting process. Beginning with load introduction, this paper recommends the proper steps in creating and utilizing an accurate weighing vessel for a particular application. It addresses the application of load cells in both weighing and force sensing systems. Mechanical and electronic force measurement principles are explained, in addition to providing a comprehensive glossary of terms. The objective is to provide readers with a solid understanding of basic weighing system principles and characteristics. Section II: Weigh Modules presents a complete definition of every popular load cell design to enable the reader to confidently choose the best design for a particular application. In addition to explaining how various designs sense load, application drawings illustrate how the technology is applied in the field. Section III: Installation and Service Guidelines is filled with information that both the novice and experienced scaleman will find helpful. A valuable reference document, this section contains information compiled by Rice Lake Weighing Systems? staff over many years. Countless service technicians and engineering professionals were consulted on mechanical, electro-mechanical, and fully electronic weighing systems. The resulting information bridges generations, yet compiles the material into brief, easy-to-understand ?tips of the trade.? %B 59th Annual Conference, St. Louis, Missouri, June 5-7 %I Society of Allied Weight Engineers, Inc. %C St. Louis, Missouri %P 42 %8 6/5/00 %G eng %U https://www.sawe.org/papers/3021/buy %9 9. WEIGHING EQUIPMENT %M 3021 %1 Non-Member Price: $21.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 21 %4 SAWE3021 %0 Conference Paper %B 57th Annual Conference, Wichita, Kansas, May 18-20 %D 1998 %T 2443. Certification and Calibration of Weighing Devices: Introduction to the Certification and Calibration Process and Implicat %A Browne, M %K 09. Weighing Equipment %X High Capacity weighing equipment is frequently installed, serviced, and used by personnel generally not familiar with advanced measuring principles. These users have come to expect 0.1% uncertainty performance with 5 to 100 ton loads. How is this possible? What is the total system that is used to deliver this performance? The needs and practices of commerce have strongly influenced the high capacity weighing industry. This paper explores the certification, installation, and routine calibration process used by the weighing industry. The related issues of specification, sealing, and calibration intervals are explored. %B 57th Annual Conference, Wichita, Kansas, May 18-20 %I Society of Allied Weight Engineers, Inc. %C Wichita, Kansas %P 12 %8 5/18/98 %G eng %U https://www.sawe.org/papers/2443/buy %9 9. WEIGHING EQUIPMENT %M 2443 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE2443 %0 Conference Paper %B 56th Annual Conference, Bellevue, Washington, May 19-21 %D 1997 %T 2393. Aircraft Weighing Equipment: A Cost Analysis %A Peterson, E %K 09. Weighing Equipment %X Since 1990, the technology of weighing equipment used on commercial aircraft has improved tremendously. The weighing equipment of today's market enables users to complete weight and balance tasks more efficiently and reliably while improving the overall accuracy of the results. The decision of the potential buyer on which type of equipment is best for their application - top of jack load cell kits or drive on platform scales - depends on both their objectives and budget. An analysis must therefore be made to explore advantages and disadvantages of each method and then relate them to the initial up front investment as compared to the long term operational cost. As a manufacturer of both types, we are frequently asked which method is better. It is our position that each company's objectives and requirements may immediately indicate which method is best for the application. We therefore assist them in analyzing all of their requirements in an attempt to determine the answer. The decision of which type of weighing equipment to purchase must therefore be based on two criteria: 1. Does the weighing equipment meet the objectives and is it suitable for the application? 2. Is the price of the weighing equipment within budgetary limitations and is it justifiable? Advantages and disadvantages to both methods and their compliance to the application must first be considered to ensure either method will meet the objectives of the user. The purchase price may not even be an issue if one method is not suitable for the application. But because the purchase price of top of jack load cell kits is so much less than that of a platform system, potential customers often do not consider the latter method because it is seen as prohibitively expensive. This study will identify the main advantages and disadvantages to each method to demonstrate how an airline or maintenance center can determine if the weighing equipment can meet the objectives and criteria of the user. The main purpose of this paper, however, is to demonstrate the operational costs of either method in an attempt to identify any savings derived therein. For it is the operational cost savings, and not just the purchase price, that must be considered to determine which method is most cost effective and thus, best suited for the application. In order to determine if the type of weighing equipment available in the market can meet the objectives and criteria of the user, a brief description of the weighing equipment and their inherent advantages and disadvantages must be reviewed. %B 56th Annual Conference, Bellevue, Washington, May 19-21 %I Society of Allied Weight Engineers, Inc. %C Bellevue, Washington %P 12 %8 5/19/97 %G eng %U https://www.sawe.org/papers/2393/buy %9 9. WEIGHING EQUIPMENT %M 2393 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE2393 %0 Conference Paper %B 54th Annual Conference, Huntsville, Alabama, May 22-24 %D 1995 %T 2264. Updated Technology Forecast for VTOL Aircraft in the Year 2020 %A Wampach, J M %K 09. Weighing Equipment %X (None - PRESENTATION) %B 54th Annual Conference, Huntsville, Alabama, May 22-24 %I Society of Allied Weight Engineers, Inc. %C Huntsville, Alabama %P 19 %8 5/22/95 %G eng %U https://www.sawe.org/papers/2264/buy %9 9. WEIGHING EQUIPMENT %M 2264 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE2264 %0 Conference Paper %B 53rd Annual Conference, Long Beach, California, May 23-25 %D 1994 %T 2193. Accuracy in Weighing Aircraft: Second and Third Order Effects and Techniques for Their Corrections %A Kroll, M W %K 09. Weighing Equipment %X The first order effect of the application of an aircraft's mass to a load cell is to generate an output voltage shift proportional to the mass. Second order effects influencing this output include the geometrical nonlinearities from integrating the stress-strain effect on a spring element. Other second order influences include temperature vs. span, altitude and latitude vs. the mass/weight ratio, and the angle of the platform surface. Vibration and wind effects could also be considered second order influences. Third order effects include material nonlinearities, hysteresis, creep, and residual side loads. This paper will discuss the genesis of these various effects and the correction techniques that are established along with some possible solutions for the future. Present fully electronic strain gage load cell aircraft scales are capable of weighing aircraft to an accuracy of about 0.1% or 1000 ppm. Without compensation for effects due to such things as latitude, altitude, and wing lift this error grows to 1%. With advanced calibration techniques and mathematical tracking of second and third order effects the error in aircraft should be reducible to about 100 ppm. %B 53rd Annual Conference, Long Beach, California, May 23-25 %I Society of Allied Weight Engineers, Inc. %C Long Beach, California %P 24 %8 5/23/94 %G eng %U https://www.sawe.org/papers/2193/buy %9 9. WEIGHING EQUIPMENT %M 2193 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE2193 %0 Conference Paper %B 52nd Annual Conference, Biloxi, Mississippi, May 24-26 %D 1993 %T 2127. Industry Standards and How Important They Are to Mass Properties Measuring Equipment %A Kroll, R %K 09. Weighing Equipment %X Many people are gun shy when it comes to ""government"" regulations and processes. However"" once we get used to the concept and understand the process"" we learn to appreciate the value and importance of ""specifying and certifying."" Consider"" for example the frozen entree section in the neighborhood grocery store. If someone wants a low-calorie"" low-fat, Or low-salt entree"" they have to be able to judge which entree to pick. Governmental standards imposed by the FDA fry to regulate and standardize information. Intercomp Company has been manufacturing high capacity and high accuracy weighing systems for fifteen years, The majority of the scales we manufacture are supplied to industries that require certification to ensure that the equipment complies with standards of accuracy"" performance"" and permanence. For nearly ten years"" Intercomp has supplied portable truck scales to the trucking"" law enforcement"" and defense industry. As an example"" the Texas Department of Public Safety uses approximately 1,500 of our portable truck scales to ensure vehicles do not exceed various weight restrictions. Weight restrictions exist on roadways throughout the world. These limitations are enforced to prevent road damage and protect the safety of others traveling on roadways. Before we can sell our portable truck scales to customers"" we must have certification from various agencies to verify the equipment meets standards of accuracy and performance. There are numerous manufacturers of portable truck scales in the U.S. How does the end user know he/she is purchasing a scale that performs to desired specifications? Furthermore"" why do industries throughout the world require most scales to be certified or meet some type of a federal standard. The user of a truck scale can be assured a scale is accurate and reliable because it has been certified by a federal or state agency of weights and measures. The scale has been tested and approved to meet a list of criteria. Virtually everything we buy and utilize in life has at some point or another been weighed. Virtually everything that is weighed must be weighed on a certified scale. The scales which aircraft are weighed upon are exempt from any type of standardized certification. Millions of passengers fly each year on billions of dollars worth of aircraft that are weighed on equipment that is never subjected to standardized certification. How can you"" the people responsible for the use of the weighing equipment"" be assured the scales you are utilizing meet worldwide standards for accuracy"" reliability"" and permanence? In other words"" how can you be sure the scale you weigh your aircraft upon is as reliable as the truck scale"" meat scale"" or any other scale used today? There are several organizations and federal agencies that enforce compliance and set calibration standards for scales. This paper will introduce you to these organizations and agencies that you may or may not be familiar with"" and hopefully present you with new ways of developing preexisting criteria. These criteria can then be considered for the purchase"" certification"" and use of scales so that you to can be assured that the equipment you utilize is accurate and reliable. %B 52nd Annual Conference, Biloxi, Mississippi, May 24-26 %I Society of Allied Weight Engineers, Inc. %C Biloxi, Mississippi %P 45 %8 5/24/93 %G eng %U https://www.sawe.org/papers/2127/buy %9 9. WEIGHING EQUIPMENT %M 2127 %1 Non-Member Price: $22.50; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 22.5 %4 SAWE2127 %0 Conference Paper %B 52nd Annual Conference, Biloxi, Mississippi, May 24-26 %D 1993 %T 2130. INF Missile Inspections/Verification by Weighing %A Lindberg, G %K 09. Weighing Equipment %X The On-Site Inspection Agency (OSIA) is a joint-service Department of Defense organization responsible for implementing inspection, escort, and monitoring requirements under the verification provisions of U.S. international arms control treaties. With headquarters located at Dulles Internatioanl Airport in Washington, D.C., the Agency has field offices at Travis Air Force Base, California; Magna, Utah; Yokota Air Base, Japan; Rhein-Main Air Base, Germany; Votkinsk, Russia; and the U.S. Embassy in Moscow. Approximately 700 men and women from the U.S. Army, Navy, Air Force, Marines, and Federal Civil Service are assigned to OSIA. OSIA was formed in January 1988 to implement the on-site inspection, escort, and continuous monitoring provisions of the Intermediate-Range Nuclear Force (INF) Treaty between the United States and former Soviet Union. The motto of OSIA, ""trust, but verify,"" was conveyed by former President Ronald Reagan to then Soviet Union President Mikhail Gorbachev when they signed the INF Treaty on December 8, 1987. OSIA has subsequently been assigned similar inspection, escort, and monitoring responsibilities of other U.S. international arms control agreements. Since July 1991, OSIA has served as the executive agent for Defense Department support to the United Nations Special Commission (UNSCOM) on Iraq. OSIA coordinates military services' provision of facilities, supplies, equipment, personnel and other assistance to UNSCOM which is charged with overseeing the destruction of Iraq's weapons of mass destruction. Most recently, OSIA has been assisting the Department of State in providing humanitarian aid to the peoples of the former Soviet Union as part of Operation Provide Hope. Since February 1992, OSIA teams have distributed more than 27,000 tons of food and medical supplies at 51 locations in the 12 republics of the former Soviet Union. %B 52nd Annual Conference, Biloxi, Mississippi, May 24-26 %I Society of Allied Weight Engineers, Inc. %C Biloxi, Mississippi %P 20 %8 5/24/93 %G eng %U https://www.sawe.org/papers/2130/buy %9 9. WEIGHING EQUIPMENT %M 2130 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE2130 %0 Conference Paper %B 49th Annual Conference, Chandler, Arizona, May 14-16 %D 1990 %T 1935. Toledo Scale Digitol %A Zelazny, J D %K 09. Weighing Equipment %X Mechanical mechanisms for determining weight have been with us since prehistoric times and are still in use today but are rapidly becoming a thing of the past. Toledo Scale, the largest scale manufacturer in the world, has not manufactured mechanical scales in the United States for many years now. Since the late 1960's or early 1970's, the strain gage load cell has been the primary device for sensing force for weighing purposes. In 1989, Toledo Scale introduced to industry what they consider to be the next logical step in the advancement of weighing technology, the DIGITOL load cell. The introduction came after five years of product development and extensive field testing. Quite simply, a dedicated microprocessor is integrated into a strain gage load cell to take advantage of the many capabilities of the microprocessor and provide many benefits for the manufacturer and the end user. %B 49th Annual Conference, Chandler, Arizona, May 14-16 %I Society of Allied Weight Engineers, Inc. %C Chandler, Arizona %P 14 %8 5/14/90 %G eng %U https://www.sawe.org/papers/1935/buy %9 9. WEIGHING EQUIPMENT %M 1935 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE1935 %0 Conference Paper %B 48th Annual Conference, Alexandria, Virginia, May 22-24 %D 1989 %T 1881. Lockheed Missiles and Space Company Mass Properties Facility %A Strom, G %K 09. Weighing Equipment %X This paper describes the mass properties balancing facility constructed in 1987 at Lockheed Missiles & Space Co. in Sunnyvale, California. The balancing machine is a Schenck-Trebel model E6/MOI-7. The capabilities and operational procedures of the machine are described. To speed up the determination of balance weights required, a program was written for a Macintosh SE computer. The capabilities of this program are outlined. %B 48th Annual Conference, Alexandria, Virginia, May 22-24 %I Society of Allied Weight Engineers, Inc. %C Alexandria, Virginia %P 17 %8 5/22/89 %G eng %U https://www.sawe.org/papers/1881/buy %9 9. WEIGHING EQUIPMENT %M 1881 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE1881 %0 Conference Paper %B 48th Annual Conference, Alexandria, Virginia, May 22-24 %D 1989 %T 1882. Aircraft Platform Scales Without Sideload Induced Weighing Errors %A Studlien, E %K 09. Weighing Equipment %X Since the introduction of electronic load cells in aircraft weighing, sideload errors have plagued the industry. Sideload errors are simply inherent in most, if not virtually all, load cells and little could really be done about it - until the advent of the Metrox Platform. In the early part of this decade, North American Rockwell developed a requirement for an all-new state-of-the-art platform scale system for the B-lB Bomber. Metrox won the contract to design and build a platform system to these stringent requirements. Initial tests of the first platforms built for the B- I B program once again revealed the old bug-a-boo-sideload errors. The sideload problem was eliminated by re-designing the load beam mounting. Instead of a fixed, solidly bolted load beam, it was mounted so it could ""float"". %B 48th Annual Conference, Alexandria, Virginia, May 22-24 %I Society of Allied Weight Engineers, Inc. %C Alexandria, Virginia %P 8 %8 5/22/89 %G eng %U https://www.sawe.org/papers/1882/buy %9 9. WEIGHING EQUIPMENT %M 1882 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE1882 %0 Conference Paper %B 48th Annual Conference, Alexandria, Virginia, May 22-24 %D 1989 %T 1883. State of the Art Mass Properties Lab %A Garcia, J %K 09. Weighing Equipment %X This paper describes the state of the art Mass Properties Laboratory at the McDonnell Douglas Helicopter Company in Mesa, Arizona. The lab's prime capabilities include: weight and center of gravity measurement; static balancing of helicopter main rotor blades; inertia measurement; and dynamic balancing of helicopter rotor hubs, complete tail rotor assemblies, and NOTAR (No Tail Rotor) fans. The theory behind the operation of each system as well as its basic requirements is described in detail. These requirements involve accuracy, repeatability, linearity, simplicity, maintainability, calibration and temperature correction, and size and weight limits. The mass properties lab and its features are the result of management foresight and cumulative years of experience in mass properties engineering. This lab, along with the entire Advanced Development Center in which it is housed, demonstrates the commitment of McDonnell Douglas Helicopter Company to be on the leading edge of technology. %B 48th Annual Conference, Alexandria, Virginia, May 22-24 %I Society of Allied Weight Engineers, Inc. %C Alexandria, Virginia %P 27 %8 5/22/89 %G eng %U https://www.sawe.org/papers/1883/buy %9 9. WEIGHING EQUIPMENT %M 1883 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE1883 %0 Conference Paper %B 47th Annual Conference, Plymouth, Michigan, May 23-25 %D 1988 %T 1846. Mews II - A Second Generation Aircraft Weighing System %A Regillo, D A %K 09. Weighing Equipment %X The present trend in both commercial and military aeronautics design involves a continual increase in the size and weight of aircraft. This increase has resulted in an industry-wide concern over the weight (and weight distribution) of the vehicles as it relates to safe flight handling of aircraft and cost effective operations. To meet these concerns, accurate and efficient aircraft weighing is a must. Of the two methods of aircraft weighing, jacking and roll-on-scale, the latter is the most popular. A new scale system, the MEWS II (Mobile Electronic Weighing System), meets the demands of the industry for a rugged, accurate, easily handled, and simply transported system of roll-on type scales. Three components make up the MEWS II system core: The weighing platform, a ramp set for access to the platform, and a platform spacer for bogie configurations. Combinations of this core adapt to various aircraft wheel configurations. Use of state-of-the art concepts and components makes the MEWS II competitive in both performance and cost. In addition, the specially designed storage/shipping pallet provided with all MEWS systems allows fast storage, inter-hangar portability, and a shipping concept that is FAA certified for compatibility with standard aircraft freight regulations. %B 47th Annual Conference, Plymouth, Michigan, May 23-25 %I Society of Allied Weight Engineers, Inc. %C Plymouth, Michigan %P 12 %8 5/23/88 %G eng %U https://www.sawe.org/papers/1846/buy %9 9. WEIGHING EQUIPMENT %M 1846 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE1846 %0 Conference Paper %B 45th Annual Conference, Williamsburg, Virginia, May 12-14 %D 1986 %T 1721. The Variation of Gravity and Its Application to the Measurement of Weight %A Drew, A R %K 09. Weighing Equipment %X The measurement of the weight of a stationary object on the surface of the Earth is the measurement of a force. This force is the sum of the gravitational attractions of the Earth, Moon and Sun and the centrifugal force caused by the rotation of the Earth. Because the acceleration of gravity varies over the Earth, the weight of an object also varies from place to place. The variations in the acceleration of gravity due to changes in height above sea level and to changes in latitude can be expressed by simple formulas. The magnitude of these variations is slightly less than 11 of the total gravitational acceleration over the surface of the Earth, and is about 0.2% over the contiguous United States. Variations due to other causes are smaller, but may be significant in high-precision weight measurements. The variations due to the tidal accelerations of the Sun and the Moon (which may reach approximately 0.003% of the total acceleration of gravity) can be calculated by complex formulas or can be derived from continuous observations. The changes due to all other causes (such as mass density changes within the crust of the Earth) cannot be calculated by theory alone. The gravitational variations due to these causes must be directly measured or be estimated using deterministic formulas based on the statistical reduction of measured data. Thus, equipment used for precise weight measurements and moved after being calibrated may be in error by a significant amount. %B 45th Annual Conference, Williamsburg, Virginia, May 12-14 %I Society of Allied Weight Engineers, Inc. %C Williamsburg, Virginia %P 8 %8 5/12/86 %G eng %U https://www.sawe.org/papers/1721/buy %9 9. WEIGHING EQUIPMENT %M 1721 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE1721 %0 Conference Paper %B 43rd Annual Conference, Atlanta, Georgia, May 21-23 %D 1984 %T 1581. Applying Shear Beam Load Measuring Techniques to Portable Platform Scales for Aircraft Weighing %A Nelson, H %K 09. Weighing Equipment %X WWEICO’s Aircraft Weighing System uses a highly accurate and sensitive technique of load measurement by sensing shear deflection in the weighing platform structure. The basic weight measurement technique has been proven in WEICO’s on-board weight and balance system in numerous aircraft applications, and when used with digital electronic computation provides a modular, easily transportable system which is adaptable to any size airplane. The system is designed to measure gross weight to within 0.10 percent and to calculate center of gravity to within 0.2 percent MAC. The weighing system is built from five portable components: The platform scales, scale access ramps, the spacer platforms, the cable assemblies, and the digital system electronics; the number of each component type required is determined by the types of aircraft to be weighed. The weighing process is easy and straightforward. One or two men are required for unloading the scales and ramps from their mobile storage container and positioning them for the weighing. One cable assembly is connected from each scale to the computer. The computer guides the operator through the weighing procedure from the time of cable connection, by providing “prompts” on the CRT display unit. The aircraft is rolled onto the platform scales via the access ramps. The computer interprets the output from the scales via the access and displays the gross weight and center of gravity on the alpha-numeric display unit. A hard copy printed record of the weighing is provided. Personnel require only a few minutes training to learn to operate the system. The computer can also interface with the WEICO on-board WBTMS for calibration purposes by use of a special interface card allowing the on-board system to be automatically calibrated from the ground without anyone on board the aircraft. The system sets new standards of performance and provides many new operational features to facilitate the required periodic aircraft weighing and weight record-keeping process at minimum cost to aircraft operators. %B 43rd Annual Conference, Atlanta, Georgia, May 21-23 %I Society of Allied Weight Engineers, Inc. %C Atlanta, Georgia %P 18 %8 5/21/84 %G eng %U https://www.sawe.org/papers/1581/buy %9 9. WEIGHING EQUIPMENT %M 1581 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE1581 %0 Conference Paper %B 43rd Annual Conference, Atlanta, Georgia, May 21-23 %D 1984 %T 1612. Small Mass Measurement Instrument - for Measuring Weight Under Weightless Conditions %A Solberg, R F %K 09. Weighing Equipment %X Animal metabolic function tests and other experiments to be conducted by the National Aeronautics and Space Administration (NASA) on the Space Shuttle require equipment for accurate determination of weight, or mass. Standard weighing equipment requires a gravity field for operation, so equipment designed to provide an accurate weighing capability in a near zero gravity environment had to be developed to fulfill NASA's requirements. The small mass measurement instrument (SMMI) was developed by Southwest Research Institute (SWRI) for NASA to fill this need. It can be used to measure small animals, biological samples, and other items. The SMMI is included in the life sciences laboratory equipment (LSLE), which will support life sciences payloads and experiments on Spacelab. The SMMI is based upon technology developed earlier for the Skylab missions. The SMMI has characteristics of a simple oscillating spring-mass system for which the period of oscillation is a function of the mass of the system. The inertial characteristics of mass are used to measure that mass. Significant work was performed to greatly expand the specimen range, improve the stability and repeatability, and increase the accuracy for this model of the SMMI. The semiautomatic instrument has the capacity to measure specimens from less than 0.002 pound (one gram) to over 22 pounds (10,000 grams) with an accuracy on the order of ~0.05 per cent. The SMMI has a key board, liquid crystal display, and microprocessor, which provide capabilities for entering and deleting data, display of messages or prompts and specimen weight values, memory, and self-calibration features. The SMMI has been tested, certified, and accepted by NASA and is scheduled for use beginning with Spacelab 4. %B 43rd Annual Conference, Atlanta, Georgia, May 21-23 %I Society of Allied Weight Engineers, Inc. %C Atlanta, Georgia %P 17 %8 5/21/84 %G eng %U https://www.sawe.org/papers/1612/buy %9 9. WEIGHING EQUIPMENT %M 1612 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE1612 %0 Conference Paper %B 42nd Annual Conference, Anaheim, California, May 23-25 %D 1983 %T 1505. Interchangeability and Improved Weighing Techniques %A First, D %K 09. Weighing Equipment %X Accurate and reliable weight/mass measurements with load cells require reliable procedures as well as accurate/reliable measurement instrumentation. This paper describes a procedure, utilizing currently available instrumentation, which simplifies recertification logistics, improves utilization of existing hardware, eliminates disastrous effects on program schedule of instrument failure, while maintaining or improving overall weighing accuracy. Today's "typical" weighing system consists of two parts, a digital display instrument and load cells. Once certified as a system, these parts are "married" forever. If one part of the system fails, or is damaged, the complete system must be returned for recertification. Obviously no weighing can take place while the system is being re-certified. The weighing system discussed in this paper adds a third component to the above described system (a Standardizer) and modifies the instrument specifications so that the instrument calibration is independent of load cell and cable characteristics. (Interchangeability) In an Interchangeable system the load cell and Standardizer are independently certified and then the instrument is certified by the Standardizer. Thus the load cell and instrument are no longer married. The Gage and Standards Center, Naval Weapons Station, Seal Beach, Pomona Annex has been using the Interchangeability concept for about 18 years. The recertification cycles which they use for the various weighing system components are shown and, recertification data taken on two load cells over a five year period are included in Appendix 1. Appendix 11 shows typical resolution, accuracy, Interchangeability etc. specifications that are obtainable with present day instrumentation. %B 42nd Annual Conference, Anaheim, California, May 23-25 %I Society of Allied Weight Engineers, Inc. %C Anaheim, California %P 31 %8 5/23/83 %G eng %U https://www.sawe.org/papers/1505/buy %9 9. WEIGHING EQUIPMENT %M 1505 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE1505 %0 Conference Paper %B 42nd Annual Conference, Anaheim, California, May 23-25 %D 1983 %T 1507. The Bonded Strain Gage Load Cell %A Jensen, H L %K 09. Weighing Equipment %X The intent of this paper is to be an information and practice application note dealing with Bonded Strain Gage load cells and their use in Precision Mass and Force Measurement. It is not intended to be the definitive work on Electronic Mass and Force Measurement, it is intended to be a guide to better understanding and communication, thereby increasing the probability of a successful application design. The readership to whom this is directed covers the range from the person who has no knowledge of electronic weighing to the person who is the department Instrumentation Specialist. The reader is encouraged to "understand what he-she knows" and practice the truism that "the only dumb question is the one you DON'T ask". The definitions and design discussions are based on years of experience in working with the demanding requirements of mass measurement for space vehicles, and force measurement and control in industry. The Bibliography lists reference material that can be considered an informal Post Graduate course in Gravimetry. Its principal value is to provide the reader with an understanding of the subject so that meaningful questions can be asked and incomplete or misleading answers questioned. Also included is reference material of significant value to both the person designing a precision weighing procedure and the person reducing the weighing procedure data. The reader is encouraged to not accept information until there is full understanding of what is being said and not said, specsmanship is to be questioned. %B 42nd Annual Conference, Anaheim, California, May 23-25 %I Society of Allied Weight Engineers, Inc. %C Anaheim, California %P 21 %8 5/23/83 %G eng %U https://www.sawe.org/papers/1507/buy %9 9. WEIGHING EQUIPMENT %M 1507 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE1507 %0 Conference Paper %B 42nd Annual Conference, Anaheim, California, May 23-25 %D 1983 %T 1508. The "Hael" System; State of the Art Platform Weighing Equipment %A Lindberg, G L %A Edwards, G R %K 09. Weighing Equipment %X Aircraft weiqhinq has traditionally been accomplished using an electronic strain gauge load cell, fitted into a socket mounted on a jacking post. The load cell is configured to match a ball attached to the jack point of the aircraft. These jack points are usually on either side of the aircraft, attached to the wing, and on the nose. The only alternative has been to use platform scales which have proven to be either inconsistent or too expensive. Now a new method using Hydraulic Actuated Electronic Load (HAEL) cells; and a high strength platform promises to give the necessary accuracy at the cost-effectiveness of a hydraulic system. %B 42nd Annual Conference, Anaheim, California, May 23-25 %I Society of Allied Weight Engineers, Inc. %C Anaheim, California %P 25 %8 5/23/83 %G eng %U https://www.sawe.org/papers/1508/buy %9 9. WEIGHING EQUIPMENT %M 1508 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE1508 %0 Conference Paper %B 40th Annual Conference, Dayton, Ohio, May 4-7 %D 1981 %T 1404. Primary System Certification Considerations for On-Board Weight and Balance Systems %A Nelson, H K %K 09. Weighing Equipment %X Many aircraft operators and aviation regulatory agencies are interested in a certifiable on-board weight and balance system for use in lieu of the conventional calculated manifest weight and center of gravity data. WEICO Corporation is committed to provide such a system to the aviation industry. The basic requirements for certification of an on-board real-time primary weight and balance system are outlined and the basic abilities of the several available on-board systems t o meet these requirements are compared in terms of their inherent and fundamental characteristics. The available systems are shown to differ fundamentally in their abilities to meet primary system certification requirements, when configured with the minimum components to do the basic measurements. Certification of several of these systems is probably not practical. Tailoring of the certification program to the basic system and sensor approach will certainly be necessary. The certification process will be enhanced by the early involvement and commitment of the aircraft manufacturers as well as the equipment manufacturer, aircraft operators, and regulatory agencies. %B 40th Annual Conference, Dayton, Ohio, May 4-7 %I Society of Allied Weight Engineers, Inc. %C Dayton, Ohio %P 10 %8 5/4/81 %G eng %U https://www.sawe.org/papers/1404/buy %9 9. WEIGHING EQUIPMENT %M 1404 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE1404 %0 Conference Paper %B 39th Annual Conference, St. Louis, Missouri, May 12-14 %D 1980 %T 1339. Test Procedures Used in Determining Aircraft Suitability for STAN* Integral Weight and Balance System %A Hawkins, B J %K 09. Weighing Equipment %X Prior to Fairchild committing to produce a STAN Integral Weight and Balance System for a new aircraft type, it is necessary for us to conduct extensive testing of a minimum of two aircraft of the type to be equipped. Such testing is described in detail including the use of Peak Pressure, Averaging Tests and Taxi Tests. Actual examples of recent tests conducted wi l l be used to illustrate the data formats used and the data obtained. %B 39th Annual Conference, St. Louis, Missouri, May 12-14 %I Society of Allied Weight Engineers, Inc. %C St. Louis, Missouri %P 21 %8 5/12/80 %G eng %U https://www.sawe.org/papers/1339/buy %9 9. WEIGHING EQUIPMENT %M 1339 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE1339 %0 Conference Paper %B 39th Annual Conference, St. Louis, Missouri, May 12-14 %D 1980 %T 1341. Development and Testing of a New Technology Weight and Balance Indicator %A Nelson, H K %K 09. Weighing Equipment %X New technology has been applied to the design and development of a cockpit indicator for aircraft weight and balance data. The system overcomes the design, reliability and maintainability deficiencies of previous systems and promises to provide sufficient operational reliability to be certifiable as a primary loading system. Extensive laboratory and flight testing is preceding the introduction of the new system into airplane service. The system is now available in production configurations for several aircraft and will become operational on most types of commercial transport aircraft in the early 1980’s The new system is not only free from most of the problems of previous systems, but offers many operational features – such as in-flight weight/CG data, auto zero, auto-calibration, low tire detection – which were impossible on earlier systems. Thus, the new system is expected to set new standards of performance for the 1980’s. %B 39th Annual Conference, St. Louis, Missouri, May 12-14 %I Society of Allied Weight Engineers, Inc. %C St. Louis, Missouri %P 16 %8 5/12/80 %G eng %U https://www.sawe.org/papers/1341/buy %9 9. WEIGHING EQUIPMENT %M 1341 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE1341 %0 Conference Paper %B 39th Annual Conference, St. Louis, Missouri, May 12-14 %D 1980 %T 1383. Design, Fabrication, Calibration, Application, and Testing of Advanced Aircraft Weighing Systems %A Ursell, C R %A Godsey, J D %K 09. Weighing Equipment %X The objective of this research effort was to apply the knowledge gained from the development of the individual load cell and read out system on the prior contract to a production weighing system consisting of on-top-of-jack load cells for level weighings and under tire platforms for ground attitude weighings. Part of the task requires development of a program for correction of c.g. from ground attitude to level position. The approach was to design, fabricate, assemble, calibrate, and demonstrate these two systems for accuracy, linearity, repeatability, and simplicity by weighing an aircraft. Also, the aircraft was weighed at various out-of-level positions and a program developed from which a curve can be plotted indicating out of level angle versus c.g. correction factor. Significant results of this developmental program are that an aircraft can be weighed repeatedly to plus or minus one pound and can be weighed in the ground attitude and corrected to the level attitude with a high degree of accuracy. Vertical location of the vertical c.g. would aid in the accuracy of the calculations. It appears that an aircraft can be weighed more accurately on the platforms than with the on-top-of-jack load cells because of the numerous forces that enter the picture when using three or more jacks interfacing with the on-top-of-jack load cell which in turn interfaces with the jack pads on the aircraft and the bottom of the jack interfaces with the floor. The next most significant results noted in the development and application of the weighing system is the temperature effect, especially at temperatures below 60ºF (16ºC). Temperature profiles were conducted on both the newly developed load cells and platforms as well as one of the current weighing systems being used by USAF. The corrections for temperature change are significant. The systems exceeded the 0.1% requirement for accuracy. The application resulting from this program is for weighing aircraft, either in a level position on-top-of-jacks or on platforms in a normal ground attitude to an accuracy of ± one pound per platform or load cell or ± 3 pounds (1.4 kg) per aircraft. It is recommended that all aircraft weighing systems employ a load cell with side load cancelling features. Due to the risk associated with the weighing of aircraft on top of jacks, it is recommended that the ground attitude weighing system be considered with development of the appropriate correction curves. %B 39th Annual Conference, St. Louis, Missouri, May 12-14 %I Society of Allied Weight Engineers, Inc. %C St. Louis, Missouri %P 44 %8 5/12/80 %G eng %U https://www.sawe.org/papers/1383/buy %9 9. WEIGHING EQUIPMENT %M 1383 %1 Non-Member Price: $22.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 22 %4 SAWE1383 %0 Conference Paper %B 37th Annual Conference, Munich, West Germany, May 8-10 %D 1978 %T 1209. Advanced Aircraft Weighing Systems %A Raskin, S H %A Ursell, C R %K 09. Weighing Equipment %X This paper is presented to convey analytical and experimental results of a program sponsored by the United States Air Force to investigate the state of the art of force measurement devices, primarily as applied to aircraft weighing. A 20,000-pound (9,072-kg) capacity load cell of new design was tested to a readout resolution of 1 pound (0.4536 kg). The load cell and readout was found to be linear to 0.0075% of applied load or 0.4 pounds (0.181 kg), whichever is greater, over a range of from 1% to 100% of the cell capacity. Maximum readout errors during tests under vertical weight force were 0.06% of applied load or 1 pound (.4536 kg), whichever is greater. The effect of side loads, acting on the load cell during measurement of vertical weight forces, also was investigated. The effects of these side loads, equivalent to 30% of various applied vertical loads, produced up to 14 pounds (6.35 kg) of error in measurement of vertical force. Tests further indicated that the new design has merit for application to weighing of aircraft on jacks, weighing on platforms, and other non-weighing applications as, for example, direct measurement of jet engine and rocket engine thrust. Published specifications for typical commercially available measurement devices are examined herein. Calibration methods are examined relative to expected field conditions. Recommendations are made for reconciling equipment specifications and tolerances with expected field conditions. %B 37th Annual Conference, Munich, West Germany, May 8-10 %I Society of Allied Weight Engineers, Inc. %C Munich, West Germany %P 24 %8 5/9/78 %G eng %U https://www.sawe.org/papers/1209/buy %9 9. WEIGHING EQUIPMENT %M 1209 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE1209 %0 Conference Paper %B 37th Annual Conference, Munich, West Germany, May 8-10 %D 1978 %T 1213. Primary Operation With an Electronic Weight & Balance System on B747 Aircraft %A Prochaska, P %K 09. Weighing Equipment %X The B747 was the first Lufthansa aircraft originally equipped with an electronic strain gage weight & balance system. This system determines electronically with axle mounted strain gage transducers the Take-Off Gross Weight (TOGW) in kg and the Center of Gravity (CG) in % MAC. The basic purpose of the system was to achieve confidence in the load and trim data sheet data. This confidence is obtained by comparison of the independent weight & balance indication with the load and trim sheet data, which is calculated with statistical standard weights. After the first period where we experienced a good system performance we started an investigation with the target to operate the weight & balance system in primary mode. The advantage of the primary operation would be the deletion of load and trim sheet with several corresponding economical and operational benefits. In addition this would result in a safety increase by higher accuracy of the weight & balance data and prevention of load and trim sheet calculation errors and loading errors. To achieve the approval from the German Airworthiness Authority for primary operation, LH demonstrated with an extended evaluation program that system accuracy, reliability and self test capability is sufficient. LH received the authority approval and will start primary operation of the B747 Weight & Balance System beginning in 1979. %B 37th Annual Conference, Munich, West Germany, May 8-10 %I Society of Allied Weight Engineers, Inc. %C Munich, West Germany %P 18 %8 5/9/78 %G eng %U https://www.sawe.org/papers/1213/buy %9 9. WEIGHING EQUIPMENT %M 1213 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE1213 %0 Conference Paper %B 34th Annual Conference, Seattle, Washington, May 5-7 %D 1975 %T 1086. Calibration of On-Board Weight and Balance Systems %A Shapiro, B H %K 09. Weighing Equipment %X The objective of this paper is to present an overview of the various techniques available for calibrating On-Board Weight and Balance Systems. The techniques, as presented, represent a broad spectrum of weighing approaches, some of which are no longer in common usage but are included for over-all perspective. The major emphasis is on the use of weighing scales, particularly the BLH NEWS System, which uniquely lends itself to the calibration of On-Board Weight and Balance Systems. Since the system was specifically designed to determine weight and center of gravity of aircraft, it very readily lends itself to the intended calibration function. The MEWS system is described in detail to acquaint the reader with its characteristics as well as the best way of using this equipment for its intended function. %B 34th Annual Conference, Seattle, Washington, May 5-7 %I Society of Allied Weight Engineers, Inc. %C Seattle, Washington %P 6 %8 5/5/75 %G eng %U https://www.sawe.org/papers/1086/buy %9 9. WEIGHING EQUIPMENT %M 1086 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE1086 %0 Conference Paper %B 34th Annual Conference, Seattle, Washington, May 5-7 %D 1975 %T 1087. Load Cells Used to Certify Masses %A Nielsen, H A %K 09. Weighing Equipment %X This paper describes a technique for using standard strain gage load cells to certify masses, as defined in a paper by Paul Pontius of the Nat.iona1 Bureau of Standards. Specific data and equipment is described and pictured for a recent verification of 10, 000 lb weights at Edwards Air Force Base, as performed by the Navy Standards Lab., Pomona, California. While the technique is about ten years old, its review at this time is appropriate, since many agencies responsible for such work may not be aware of its existence. It was born during the urgency of the missile crisis, and perhaps did not receive proper publicity, particularly in commercial circles. In view of the current explosive acceptance of electronic weighing in industry, which often must comply with regulations that are at best technically debatable, review of this technique highlights some measurement basics which have fundamental significance for better scale design and performance. These basics are summarized in ten design goal criteria. %B 34th Annual Conference, Seattle, Washington, May 5-7 %I Society of Allied Weight Engineers, Inc. %C Seattle, Washington %P 25 %8 5/5/75 %G eng %U https://www.sawe.org/papers/1087/buy %9 9. WEIGHING EQUIPMENT %M 1087 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE1087 %0 Conference Paper %B 33rd Annual Conference, Fort Worth, Texas, May 6-8 %D 1974 %T 1033. An Oleo Settling Weight and Balance System %A Clark, D K %K 09. Weighing Equipment %X The development of a high reliability pressure type Weight and Balance system, with accurate static reading capability, is the result of four years of intensive investigation by Canadian Marconi Company into the general problem of on-board weighing systems for aircraft. Beginning with the installation of a simple pressure system on a Canadian Air Force Fanjet Falcon in 1972, the program has now advanced to an accumulation of measured data on almost all major aircraft types, including the Lockheed C-130 and L-1011, McDonnel Douglas DC-8 and DC-9 and Boeing 707, 727, and 747 aircraft, using the olea pressure curve technique. The simple pressure type Weight and Balance system operates on the principle of measuring the static pressure of each of the aircraft oleos, and electronically multiplying by the known oleo piston areas to determine the force acting on each of the landing gear. The system thus consists of a set of pressure sensors and a computer/display unit. Take-off Gross WEight (TOGW) and Center of Gravity (% MAC) are automatically computed from aircraft constants. The two main advantages of this type of system are: (1) ease of installation (2) low maintenance The first advantage derives from the fact that the sensor can be installed via the existing charge valve opening and can therefore be easily retrofitted on all aircraft types. The second advantage derives from the fact that pressure sensors have been proven to be much more stable than strain gauge sensors* thus requiring little maintenance. The major disadvantage of the simple pressure system is that it is subject to large and unpredictable errors due to oleo friction. Accordingly, Canadian Marconi Company has developed an advanced pressure system which can measure, and electronically cancel friction force error while the aircraft is in static condition, *Comments on strain gauge instability errors in the C-7A and on the 747 and DC-10 aircraft can be found in SAWE Paper No 881 by Lieutenant Colonel Edward Low, and in Kit No. 8 of the 1973 Avionics Maintenance Conference report. %B 33rd Annual Conference, Fort Worth, Texas, May 6-8 %I Society of Allied Weight Engineers, Inc. %C Fort Worth, Texas %P 7 %8 5/6/74 %G eng %U https://www.sawe.org/papers/1033/buy %9 9. WEIGHING EQUIPMENT %M 1033 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE1033 %0 Conference Paper %B 33rd Annual Conference, Fort Worth, Texas, May 6-8 %D 1974 %T 1034. What Can a Ground Weighing System Do for Us? %A Fryer, S J %K 09. Weighing Equipment %X This paper has been written to more specifically define the use of electronic weighing equipment for industry; and, in particular, the aircraft industry. The primary systems used by airlines are the load cell kits which fit on top of aircraft jacks. The newer systems are platform scales, onto which the aircraft is towed. The platform scales are used specifically for not only total weight and center of gravity, but also calibration of the on-board weighing equipments found primarily in the new wide-bodied aircraft. Additional electronic scale systems are now being installed for the cargo weighing, as well as individual baggage and sorting systems within the terminal. This is to assist direct computer input and data enhancement. The application of the new electronic scales is very important; primarily because they are portable, they have accuracies of .l%, and they can be easily used in different locations by inexperienced operators. A bad weight is typically worse than none at all; therefore, the application and use of the electronic scales is of great importance. At stake is the optimum use and safety of aircraft. %B 33rd Annual Conference, Fort Worth, Texas, May 6-8 %I Society of Allied Weight Engineers, Inc. %C Fort Worth, Texas %P 28 %8 5/6/74 %G eng %U https://www.sawe.org/papers/1034/buy %9 9. WEIGHING EQUIPMENT %M 1034 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE1034 %0 Conference Paper %B 30th Annual Conference, Newport Beach, California, May 3-5 %D 1971 %T 879. A New Design Weight and Center of Gravity Determining Fixture %A Williams, D J %A Cazier, R N %K 09. Weighing Equipment %X The Ormond Inc. Mass and Center-of-Gravity determining system, model WCG-91-2-10K was uniquely designed by Ormond Inc., Santa Fe Springs, California, under the technical direction and to the specifications of Thiokol Chemical Corporation. It is being used to measure mass and determine balance data for Minuteman Third Stage loaded chambers and pre-fired and post-fired motor assemblies. A description of the equipment, the principles of operation, calibration data and technique, accuracies, errors, and repeatability of the fixture are presented. The system is the largest device ever built which uses a mechanical beam balance for measuring mass and a separate and distinct system composed mainly of two electronic load cells for measuring center of gravity moment. The load cells measure only the off center force and, therefore, their measurement of the center-of-gravity moment is independent of the amount of weight applied to the table. Calibration data obtained during the past year demonstrates a 3sigma mass measurement repeatability of 0.023 percent and an accuracy of 0.032 percent or better of applied load throughout the usable range of 500 thru 10,'OOO pounds. Obtained center-of-gravity accuracies are 0.013 in. longitudinal, and 0.005 in, lateral and vertical (3sigma ). %B 30th Annual Conference, Newport Beach, California, May 3-5 %I Society of Allied Weight Engineers, Inc. %C Newport Beach, California %P 36 %8 5/3/71 %G eng %U https://www.sawe.org/papers/0879/buy %9 9. WEIGHING EQUIPMENT %M 0879 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE0879 %0 Conference Paper %B 30th Annual Conference, Newport Beach, California, May 3-5 %D 1971 %T 881. Testing of Two Integral Weight and Balance Systems on the C-7A %A Low, MAJ E %K 09. Weighing Equipment %X USAF mission-oriented interest in weight and balance systems led to the purchase of two prototypes for the C-7A which could be used on other aircraft. An adaptation of the Fairchild STAN strut pressure system and a BLH strain gauge were installed late in 1969. Installation and maintenance problems are included with systems descriptions, Government requirements, and test results to suggest problem areas for other insta1lations. All the systems had difficulty compensating for slope. After the Fairchild hydraulic pump was modified that system met most of the requirements. With out some agitation to reduce strut friction error it exceeded limits. The BLH system output was limited by shunting of the load away from the ax1e. It was very sensitive to weight changes and external forces, yet appeared to shift over a period of time. A need exists for weight and balance systems but it is suggested they be carefully matched to the aircraft. Reliability should receive more emphasis now placed on accuracy. %B 30th Annual Conference, Newport Beach, California, May 3-5 %I Society of Allied Weight Engineers, Inc. %C Newport Beach, California %P 10 %8 5/3/71 %G eng %U https://www.sawe.org/papers/0881/buy %9 9. WEIGHING EQUIPMENT %M 0881 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE0881 %0 Conference Paper %B 30th Annual Conference, Newport Beach, California, May 3-5 %D 1971 %T 896. The STAN/MASS System of Determining Aircraft Weight and Balance %A Hawkins, B J %K 09. Weighing Equipment %X This paper will describe some of the features of the STAN/MASS Integral Weight and Balance System as presently installed on a USAF C-7A aircraft and an airline 727B. A description of the MASS system will be offered plus some of the basic reasons behind the design which was essentially to provide high accuracy at the blocks, engines off, operational capability for the STAN system. In addition, data is presented covering the application of STAN to the USAF Speckled Trout R&D aircraft and a commentary on the present state of the art of IWBS, together with our observations regarding the overall use of these systems in airline operations. The success of the STAN system continues to grow as we add additional aircraft to our inventory of users. Presently about 200 aircraft are STAN equipped and we estimate over 2,000,000 hours of flight time have been recorded by the STAN system to date. Twenty-six different aircraft types have been equipped with STAN by over 30 operators thus demonstrating that the system is adaptable to most any aircraft type. %B 30th Annual Conference, Newport Beach, California, May 3-5 %I Society of Allied Weight Engineers, Inc. %C Newport Beach, California %P 13 %8 5/3/71 %G eng %U https://www.sawe.org/papers/0896/buy %9 9. WEIGHING EQUIPMENT %M 0896 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE0896 %0 Conference Paper %B 30th Annual Conference, Newport Beach, California, May 3-5 %D 1971 %T 898. Weighing in Place - Airline %A McCarty, J R %K 09. Weighing Equipment %X This paper discusses the implementation of an idea to permit the weighing of an airplane, utilizing load cells, while it remains on jacks during an overhaul at maintenance operation. The concept is basically that of a jack within a jack, probably is not really all that startling, but to the writer’s knowledge, has not been utilized before. Fixtures and small, low profile, short stroke, jacks were designed by a United Air Lines tool designer. Fabrication was done by outside concern. The fixtures are threaded on to the screw extension of the standard aircraft tripod jack and become a part of the jack. When it is time to weigh the airplane, the small jacks and load cells are inserted in the fixtures, the airplane is raised slightly, approximately 1/32 inch, transferring the weight to the load cells and the weight readings taken. Airplane down time for the weighing was forecast to be in the order of ten minutes. This method, which we call “weighing in place”, has been used by United Air Lines since October of 1970, has been very successful, and was approved by our local FAA in February of 1971. %B 30th Annual Conference, Newport Beach, California, May 3-5 %I Society of Allied Weight Engineers, Inc. %C Newport Beach, California %P 7 %8 5/3/71 %G eng %U https://www.sawe.org/papers/0898/buy %9 9. WEIGHING EQUIPMENT %M 0898 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE0898 %0 Conference Paper %B 29th Annual Conference, Washington, D. C., May 4-6 %D 1970 %T 816. Considerations in the Calibration on Electronic Load Cells %A Harris, E C %K 09. Weighing Equipment %X The results of repetitive calibrations of a number of precision four arm bridge load cells over several years at the McDonnell Douglas Astronautics Corporation, Western Division are presented. Two interesting and significant observations are made: (1) the cell outputs under tension loading are generally very repeatable and show no tendency to change with time; (2) the cell outputs in compressive loading are several times less repeatable than for the tension application. An explanation of the non-repeatability phenomenon in compression loading is offered. Methods and equipment for improving the repeatability of compressive calibrations are presented. A definite correlation is shown to exist between the non-repeatability of the cells and their individual sensitivities to bending moments. The concept of a coefficient of sensitivity to bending is proposed. Methods of determining this coefficient are shown. Economic and reliability aspects of the weighing function are discussed. Recommendations are presented for achieving more reliable weighing systems with appreciably lower operating costs. %B 29th Annual Conference, Washington, D. C., May 4-6 %I Society of Allied Weight Engineers, Inc. %C Washington, DC %P 26 %8 5/4/70 %G eng %U https://www.sawe.org/papers/0816/buy %9 9. WEIGHING EQUIPMENT %M 0816 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE0816 %0 Conference Paper %B 29th Annual Conference, Washington, D. C., May 4-6 %D 1970 %T 818. Aerodynamics Effects on the Measurement of Mass Properties Using a Trebel Dynamic Balancing Machine %A Green, R D %A Dearden, E %K 09. Weighing Equipment %X The work described in this paper is concerned with the measurement of mass properties of bodies using a Trebel FVD.500 Dynamic Balancing Machine, and deals specifically with bodies whose external shape is unsymmetrical about the axis of rotation. The rotation of such bodies results in an aerodynamic force which, because the balancing machine assumes that all forces are caused by rotating masses, represents an error in the measured mass properties. It would also constitute an error in dynamic balancing, because weights would be added to the body to compensate for the aerodynamic force as well as the mass forces. The measurements described in this paper were made using a Trebel Dynamic Balancing Machine, and illustrate how this machine can be used to measure aerodynamic force and so correct the machine data to give true mass properties. The relationship between machine readings and the force system all a rigid rotating body are shown to contain a term dependent upon the aerodynamic force and varying inversely as the square of the speed of rotation. This term is of appreciable magnitude at low speeds of rotation, and results in a variation of machine readings with speed of rotation. By carrying out measurements on one particular body over a range of speeds from 50 rpm to 120 rpm, the change of machine reading with speed can be determined, and from this the aerodynamic force can be computed. This process is discussed in the paper. and test results are given and analysed. The main conclusion from this work is that, when aerodynamic effects are appreciable, they can be measured on the Trebel FVD. 500 Dynamic Balancing Machine by carrying out a series of runs at different speeds of rotation in the low speed range. The experience of the authors of this paper is limited to the Trebel vertical two plane balancing machine and they cannot speak of the applicability of the methods to tests using other types of machine. However, it is their view that a basic consideration of the way in which the force system contributes to the machine readings can, as in their particular experience, be of value in appreciating the capabilities of a measuring system. %B 29th Annual Conference, Washington, D. C., May 4-6 %I Society of Allied Weight Engineers, Inc. %C Washington, DC %P 32 %8 5/4/70 %G eng %U https://www.sawe.org/papers/0818/buy %9 9. WEIGHING EQUIPMENT %M 0818 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE0818 %0 Conference Paper %B 28th Annual Conference, San Francisco, California, May 5-8 %D 1969 %T 755. STAN(R) Integral Weight and Balance System - "An Updating" %A Hawkins, B J %K 09. Weighing Equipment %X Continuous and increasing interest among the airlines and the aircraft manufacturers in Integral Weight and Balance Systems (IWBS) has resulted in developments which should be brought to the attention of these parties. The STAN(R) system, an IWBS in fairly general use, is well Known to the airline and aircraft community and the purpose of this paper is not to reiterate the design details of this system but rather to point up installations, experience and several new developments. Included in this paper will be references and some details on simplified versions of the system (AccuMAC) and associated related hardware. Operational experiences will be discussed and the application of techniques; materials and user philosophy shall also be brought out. In order not to bore them with unnecessary and redundant system description I have limited the basic IWBS concept as simple introduction and go from there into the more pertinent aspects of the subject as a whole. Proprietary data, by necessity, has been restricted but interested airline personnel (or manufacturers of aircraft) are invited to discuss these details in conference with the writer. %B 28th Annual Conference, San Francisco, California, May 5-8 %I Society of Allied Weight Engineers, Inc. %C San Francisco, California %P 28 %8 5/5/69 %G eng %U https://www.sawe.org/papers/0755/buy %9 9. WEIGHING EQUIPMENT %M 0755 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE0755 %0 Conference Paper %B 28th Annual Conference, San Francisco, California, May 5-8 %D 1969 %T 805. Test Results of an On-Board Weight and Balance System %A O'Connor, W M %K 09. Weighing Equipment %X To evaluate present and alternative methods for control of aircraft loading and determination of gross weight and center of gravity, and to determine the technical and economic feasibility of an on board aircraft weight and balance system. %B 28th Annual Conference, San Francisco, California, May 5-8 %I Society of Allied Weight Engineers, Inc. %C San Francisco, California %P 6 %8 5/5/69 %G eng %U https://www.sawe.org/papers/0805/buy %9 9. WEIGHING EQUIPMENT %M 0805 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE0805 %0 Conference Paper %B 27th Annual Conference, New Orleans, Louisiana, May 13-16 %D 1968 %T 715. Self-Calibrating Techniques on a Dead Weight Machine %A Rose, E %K 09. Weighing Equipment %X The function of a Dead Weight Machine is described. A calibration technique is presented whereby the separable components (dead weights) are calibrated directly in the Dead Weight Machine using a precision load cell as a mass comparator, thus eliminating the costly and time consuming disassembly and reinstallation process which would otherwise be required. Traceability to the National Bureau of Standards is demonstrated. Conversion from the mass unit to the force unit and possible sources of error are discussed in detail. The question of independent loading versus sequential loading is raised and the advantages of each system are analyzed. %B 27th Annual Conference, New Orleans, Louisiana, May 13-16 %I Society of Allied Weight Engineers, Inc. %C New Orleans, Louisiana %P 29 %8 5/13/68 %G eng %U https://www.sawe.org/papers/0715/buy %9 9. WEIGHING EQUIPMENT %M 0715 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE0715 %0 Conference Paper %B 26th Annual Conference, Boston, Massachusetts, May 1-4 %D 1967 %T 625. Integral Aircraft Weighing Systems %A Shapiro, B H %K 09. Weighing Equipment %X It is now possible to determine the gross weight and center of gravity of an airplane with integrally mounted transducers and instrumentation. This paper will discuss the general system requirements needed to make an effective and accurate measurement of weight and C.G. The necessary performance requirements for the major components in the system, such as the transducers and the computer, will be established. The errors, which must be minimized in order to provide an accurate and reliable system, will be discussed. Having established the criteria for an effective system, the general methods of approaching this problem will be considered. The methods to be considered will include only those concepts that are presently in use or under development. This will include a brief discussion of such concepts as the measurement of oleo strut pressure, direct force measurement, and axle deflection. Of the concepts considered, the axle shear deflection system, as developed by BLH Electronics, Inc., offers the best possible solution to the fulfillment of the established criteria. The BLH system, designated as OBAWS (On-Board Aircraft Weighing System), will be described in sufficient detail to make the reader familiar with the concepts of the system. This will include a description of the unique shear-deflection transducers which represent an important break-through in that they respond to vertical shear forces only. As a result, the system does not respond or react to side forces. Finally, transducer installation problems are discussed followed by a description of BLH installation tooling and how it is used. %B 26th Annual Conference, Boston, Massachusetts, May 1-4 %I Society of Allied Weight Engineers, Inc. %C Boston, Massachusetts %P 14 %8 5/1/67 %G eng %U https://www.sawe.org/papers/0625/buy %9 9. WEIGHING EQUIPMENT %M 0625 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE0625 %0 Conference Paper %B 24th Annual Conference, Denver, Colorado, May 17-19 %D 1965 %T 489. A Compression Weigh System Using the 'Glide-Aire' Jack Support Method %A Briggs, R P %A Rudd, A F %K 09. Weighing Equipment %X This paper presents a description of the Saturn S-IVB stage and aft interstage weight and balance system. This system is used to fulfill the contractual requirements for determination of dry stage and aft interstage mass characteristics for use in weight control and in-flight trajectory analyses. Special emphasis is given to the development of the weighing techniques and the design considerations required to obtain optimum system accuracy. These areas include: The “Glide-Aire” jack support, the flexural pivots, mechanical connections and weigh system instrumentation. System evaluation tests run to determine acceptance of the weigh system operational features and test results establishing system accuracy are explained in some detail with a graphical presentation. In conclusion, actual data from two S-IVB stage weighings are presented to show a system capable of being repeatable to within +/-0.04 percent. Perhaps even more significant is the high confidence shown during the qualification testing that this system is capable of +/-0.05 percent accuracy. %B 24th Annual Conference, Denver, Colorado, May 17-19 %I Society of Allied Weight Engineers, Inc. %C Denver, Colorado %P 32 %8 5/17/65 %G eng %U https://www.sawe.org/papers/0489/buy %9 9. WEIGHING EQUIPMENT %M 0489 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE0489 %0 Conference Paper %B 24th Annual Conference, Denver, Colorado, May 17-19 %D 1965 %T 490. A Single Point Center of Gravity and Weight Measuring System for Airborne Ejection Launched Missiles %A C L Baer %K 09. Weighing Equipment %X This paper describes and discusses a new system of center of gravity and weight determination for missiles. An order of magnitude improvement in center of gravity location accuracy is achieved. A new moment measuring device using semiconductor strain gauges is the most important factor in achieving the increased accuracy. The center of gravity locating and weight measuring systems with which the author is currently most familiar serve to establish the center of gravity position and weight of airborne missiles which are in the general size of 800 to 1200 pounds. These missiles are supported on, and ejection launched from, an airplane at two points. The pitch rate is critical for safe separation and is very sensitive to small variations in center of gravity location. The flight test program includes establishing an acceptable tolerance of variation in missile center of gravity. The new system discussed in this paper provides separate and independent measurements of missile unbalanced moment and missile weight. A “conventional approach” system which has been in use for some time employs four load cells, spaced 10 inches apart in a square pattern, connected to an automatically summing readout instrument. Because of the fact that separate direct and independent readings of missile unbalanced moment and missile weight are provided in the new system the sources of error can be isolated and analyzed more thoroughly, and the center of gravity effect of errors in the weight measurement is reduced to a negligible amount. To provide numerical simplicity in the error analysis in this paper, it is assumed that the true weight of missiles being measured is 1000.00 pounds. %B 24th Annual Conference, Denver, Colorado, May 17-19 %I Society of Allied Weight Engineers, Inc. %C Denver, Colorado %P 38 %8 5/17/65 %G eng %U https://www.sawe.org/papers/0490/buy %9 9. WEIGHING EQUIPMENT %M 0490 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE0490 %0 Conference Paper %B 23rd National Conference / Sheraton, Dallas Hotel, Southland Center, Dallas, Texas May 18-21 %D 1964 %T 441. Data Requirements and Statistical Treatment of Data for Electronic Weighing Devices %A Johnston, D L %K 09. Weighing Equipment %B 23rd National Conference / Sheraton, Dallas Hotel, Southland Center, Dallas, Texas May 18-21 %I Society of Allied Weight Engineers, Inc. %C Dallas, Texas %P 168 %8 5/18/64 %G eng %U https://www.sawe.org/papers/0441/buy %9 9. WEIGHING EQUIPMENT %M 0441 %1 Non-Member Price: $84.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 84 %4 SAWE0441 %0 Conference Paper %B 23rd National Conference / Sheraton, Dallas Hotel, Southland Center, Dallas, Texas May 18-21 %D 1964 %T 461. Introduction to and Remarks About the Metrology Panel %A Jensen, H L %K 09. Weighing Equipment %B 23rd National Conference / Sheraton, Dallas Hotel, Southland Center, Dallas, Texas May 18-21 %I Society of Allied Weight Engineers, Inc. %C Dallas, Texas %P 3 %8 5/18/64 %G eng %U https://www.sawe.org/papers/0461/buy %9 9. WEIGHING EQUIPMENT %M 0461 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE0461 %0 Conference Paper %B 22nd National Conference, St. Louis, Missouri, April 29 - May 2 %D 1963 %T 368. Learning to Live With Electronic Weighing %A Rose, E %A Harris, E C %K 09. Weighing Equipment %X This paper was presented at the Twenty-second Annual National Conference of the Society of Aeronautical Weight Engineers at St. Louis, Missouri, April 29-May 1, 1963. The decision by Douglas Aircraft Company to rely chiefly on electronic rather than mechanical systems for its overall research and development (R & D) missiles and space weighing operations was based on several considerations. These included convenience of use, portability, accuracy, and relative cost. Application of the earlier electronic systems, however, left much to be desired. End-to-end calibration was mandatory. Repairs usually necessitated return of the entire unit to the manufacturer. Additional weighing requirements, involving different capacity load cells, meant procuring a complete new system. Still another problem, although not the fault of the systems themselves, was the lack of adequate calibration and evaluation test facilities. The whole operation thus was costly, time-consuming, and otherwise unacceptable. The solution to these problems called for a re-evaluation of the overall weighing requirements. It was then possible to specify a system which would meet these requirements. Interchangeability of components was the most essential prerequisite, and upon this concept the universal system was founded. In order to verify the characteristics and capabilities of the universal system, certain tests were necessary. By establishing dead weight loading facilities at its Santa Monica, California, location, Douglas not only could perform these tests, but could also assume the responsibility for accurate periodic certification, a function previously either delegated to the National Bureau of Standards, performed by inaccurate methods, or foregone altogether. Test results did, in fact, demonstrate that load cells, cables, and even the indicating instruments themselves could be interchanged without any significant loss of accuracy. “Creep”, the change in load cell output with time, was found to vary from one cell to another; in some cells, as much as 0.05 percent creep was present. The lack of a direct reading capability, a consequence of the internal design of the universal system, necessitated the use of correction curves or tables in order to obtain the desired accuracy of 0.1 percent, but due to the nature of R&D operations, this did not detract appreciably from the system. Further tests uncovered errors in the order of 0.2 percent due to misalignment of the load cell and mechanical fittings. These tests were repeated using various flexures or pivots for isolation of loads into the cells, the results of which showed that the effect of misalignment could be virtually eliminated. Efficiency of the weighing operations was improved by initiating an IBM computer program to handle and process data. Additional improvement could be realized by standardization of test procedures, facilities, and equipment. Continued investigations are recommended to further the “state of the art” of electronic weighing, particularly with respect to compression load application. %B 22nd National Conference, St. Louis, Missouri, April 29 - May 2 %I Society of Allied Weight Engineers, Inc. %C St. Louis, Missouri %P 46 %8 5/29/63 %G eng %U https://www.sawe.org/papers/0368/buy %9 9. WEIGHING EQUIPMENT %M 0368 %1 Non-Member Price: $23.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 23 %4 SAWE0368 %0 Conference Paper %B 22nd National Conference, St. Louis, Missouri, April 29 - May 2 %D 1963 %T 387. Weighing the Atlas Silo Crib %A McCarty, C D %A Mullen, J E %K 09. Weighing Equipment %X This paper was presented at the Twenty-second Annual National Conference of the Society of Aeronautical Weight Engineers at St. Louis, Missouri, April 29-May 1, 1963. One means of storing the Air Force Atlas ICBM missile in a state of readiness is the underground unitary silo. Inside the silo, entirely suspended by shock absorbing springs, is an eight-sided steel crib structure containing all the elements necessary to launch and Atlas missile. A 50-foot tunnel connects the silo to a two-level launch control center, also underground and shock isolated. The crib suspension-system springs were stiffness calibrated by the supplier so that the crib’s elastic center could be calculated. However, the calculated weight and the center of gravity were not known to the accuracy desired. For maximum effectiveness, the elastic center of the suspension system must coincide with the crib’s center of gravity. This reduces the spurious crib perturbations and, with the action of damping units, tends to keep the oscillations vertical harmonic motions. The weighing and center of gravity determination program was undertaken to satisfy these requirements. %B 22nd National Conference, St. Louis, Missouri, April 29 - May 2 %I Society of Allied Weight Engineers, Inc. %C St. Louis, Missouri %P 14 %8 5/29/63 %G eng %U https://www.sawe.org/papers/0387/buy %9 9. WEIGHING EQUIPMENT %M 0387 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE0387 %0 Conference Paper %B 20th National Conference, Akron, Ohio, May 15-18 %D 1961 %T 248. Liquid Propellant Weight Testing for Large Ballistic Missiles %A Jensen, H L %A Mullen, J E %A Johnston, D L %K 09. Weighing Equipment %X The paper first discusses the problem from the approach of a generalized test program, start¬ing with a Customer Test request and following the various steps through the process of generating the required definitions, understandings, concurrences, and coverages (authorizing documents) that lead to a successful test program. (Portions of the paper are based on actual experience in the Atlas Missile test program.) The discussion continues through the test program to the final report to the customer. One of the most important facets of this paper is the exploration of the various "Design concept" Transducers Systems of each type (Delta Press, load cell, temper¬ature, etc .} to most adequately detect, convert, and record the phenomena it will be monitoring, an illustrative admonition to the above is "Don't measure A.C. with a D.C. meter" . The final phase of the paper deals with the reduction and analysis of the data recorded during the test sequence. The statistical methods are explored from the theoretical background through to the reduced data. An illustrative sample is included to demonstrate one particular method utilized. %B 20th National Conference, Akron, Ohio, May 15-18 %I Society of Allied Weight Engineers, Inc. %C Akron, Ohio %P 14 %8 5/15/61 %G eng %U https://www.sawe.org/papers/0248/buy %9 9. WEIGHING EQUIPMENT %M 0248 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE0248 %0 Conference Paper %B 20th National Conference, Akron, Ohio, May 15-18 %D 1961 %T 288. Secondary Force Standards for the Calibrating Weighing Equipment %A Jelinek, H N %K 09. Weighing Equipment %X This paper was presented at the Twentieth National Conference of the Society of Aeronautical Weight Engineers at Akron, Ohio, May 15 – 18, 1961. The problems of inherent in obtaining secondary force standards are discussed in this paper. The types of secondary standards discussed are: (1) proving rings (2) hydraulic load cells (3) mechanical load scales (4) electric strain gage cells. Where large capacities, up to 1,000,000 lbs. of force are required; dead weights, proving rings, or electric load cells are true secondary standards. A secondary standard is defined as force calibrating equipment one step removed from NBS dead weight primary standards. Dead weights are relatively expensive. A comparison regarding the use of proving rings or electric stress systems is made and the merits of all types of systems are summarized in a table. %B 20th National Conference, Akron, Ohio, May 15-18 %I Society of Allied Weight Engineers, Inc. %C Akron, Ohio %P 14 %8 5/15/61 %G eng %U https://www.sawe.org/papers/0288/buy %9 9. WEIGHING EQUIPMENT %M 0288 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE0288 %0 Conference Paper %B 20th National Conference, Akron, Ohio, May 15-18 %D 1961 %T 292. Inherent Accuracy Advantages of a Direct Digital Weighing System as Applied to Center of Gravity and Fuel Flow Problems %A Hall, D L %A Smith, A J %K 09. Weighing Equipment %X This paper was presented at the Twentieth National Conference of the Society of Aeronautical Weight Engineers at Akron, Ohio, May 15 – 18, 1961. Data reduction, whether the solution of specific equation for given test items, or the accumulation of data from statistical or dynamic processes, is a problem with which all in the aeronautical and allied sciences are particularly concerned. As a means of mitigating this problem, where weight data is concerned, this paper argues the case for automatic digital recording and processing of weight parameters. The more directly that weight are converted to digital form and entered into automatic processing, the higher are system accuracies. Two specific problems are cited for illustrative purposes. One is a missile motor weight and center of gravity determination in three coordinates and the other, a mass flow measuring system for volumetric meter calibration. Other processes are equally enhanced, such as digital control of automatic batch plants, and continuous feeder-weigh systems. All of these are currently of significant interest to the engineer working on missile and space programs. %B 20th National Conference, Akron, Ohio, May 15-18 %I Society of Allied Weight Engineers, Inc. %C Akron, Ohio %P 10 %8 5/15/61 %G eng %U https://www.sawe.org/papers/0292/buy %9 9. WEIGHING EQUIPMENT %M 0292 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE0292 %0 Conference Paper %B 20th National Conference, Akron, Ohio, May 15-18 %D 1961 %T 295. Electronic Scales and Precise Weight Determination %A Stacy, J W %K 09. Weighing Equipment %X This paper was presented at the 20th Annual National Conference of the Society of Aeronautical Weight Engineers at Akron, Ohio, May 15-18, 1961. In aircraft and space vehicles, precise information must be obtained concerning the actual weight and center of gravity of vehicles and components, in order to exercise control of these factors commensurate with the requirements of the vehicle and mission. The use of electronic scales in accomplishing these objectives is reported, together with information on the operation of the equipment, its maintenance and calibration. Data on the degree of precision with which actual weights have been determined is included, with procedures found necessary in calibration and use of electronic scales. The equipment reported on has been in daily use for several years. During the first few months’’ use, each system was found to have undergone a seasoning process in which significant shifts in calibration occurred. These shifts were contributed partly by the strain gage load cells and partly by the electron tube computers. Each load cell displayed a shift of different value, up to half a percent of the point reading. These shifts were compensated for by making changes in resistors in the circuits. This was done in the users’ instrument maintenance and calibration facility and proved by the use of National Bureau of standards certified test weights. Electronic scales may be used successfully in obtaining actual weight data at minimum cost, data which is consistent and accurate. Electronic scales should undergo an initial seasoning with frequent calibration. After stability has been demonstrated the time between calibrations may be lengthened to a period consistent with the amount of weighing being done. %B 20th National Conference, Akron, Ohio, May 15-18 %I Society of Allied Weight Engineers, Inc. %C Akron, Ohio %P 5 %8 5/15/61 %G eng %U https://www.sawe.org/papers/0295/buy %9 9. WEIGHING EQUIPMENT %M 0295 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE0295 %0 Conference Paper %B 18th National Conference, Henry Grady Hotel, Atlanta, Georgia, May 18-21 %D 1959 %T 228. A Universal Facility for Weight and Thrust Determination on All Current and Planned Aircraft %A Krebs, J W %K 09. Weighing Equipment %X Described is a facility designed for independent measurement of aircraft weight and thrust values for aircraft weighing up to 1.2 x 106 pounds with thrusts up to 5 x 105 pounds forward and 2.5 x 105 pounds reverse. Craft are locked down onto platforms on a concrete runway, where each platform has a weighing capacity of 3 x 105 pounds and a thrust measurement capability of 1.25 x 105 pounds; there are four platforms in total resulting in the overall facility capacities. Measurement is electronic using strain gage load cells; a remote instrument room is underground with visual and sound contact by television and radio. Weight and thrust are measured simultaneously. A fully loaded aircraft can be placed on the platform(s) and the loss in weight by fuel consumption can be accurately measured from zero, and related to both thrust and time. Instrumentation was developed around the basic null-balance potentiometer. %B 18th National Conference, Henry Grady Hotel, Atlanta, Georgia, May 18-21 %I Society of Allied Weight Engineers, Inc. %C Atlanta, Georgia %P 10 %8 5/18/59 %G eng %U https://www.sawe.org/papers/0228/buy %9 9. WEIGHING EQUIPMENT %M 0228 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE0228 %0 Conference Paper %B 18th National Conference, Henry Grady Hotel, Atlanta, Georgia, May 18-21 %D 1959 %T 235. Development of a Direct Reading Torque Scale for Mass Balancing of Control Surfaces %A Norton, D H %K 09. Weighing Equipment %X This paper was presented at the Eighteenth National Conference of the S.A.W.E. May 18-21, 1959, Henry Grady Hotel, Atlanta Georgia. This paper is concerned with a fixture, to be used by shop personnel, for the direct measurement of torque exerted by a control surface about its own hinge line. The intent of this paper is to improve on the current design. The design objective was to come up with a new tool incorporating advantages over the current older design in the following areas; 1. Increased accuracy and sensitivity. 2. A significant reduction in time required. 3. A nearly universal application, so that the same basic equipment could be used for future control surfaces by adding a few special adapters or brackets. 4. Utter simplicity of operation. %B 18th National Conference, Henry Grady Hotel, Atlanta, Georgia, May 18-21 %I Society of Allied Weight Engineers, Inc. %C Atlanta, Georgia %P 4 %8 5/18/59 %G eng %U https://www.sawe.org/papers/0235/buy %9 9. WEIGHING EQUIPMENT %M 0235 %1 Non-Member Price: $20.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 20 %4 SAWE0235 %0 Conference Paper %B 16th National Conference, Broadview Hotel, Wichita, Kansas, April 29 - May 2 %D 1957 %T 149. Electronic Load Cell Weighing in the Aircraft Field %A Riege, Arthur C %K 09. Weighing Equipment %X The idea of weighing loads and forces by electrical means is by no means new. In fact, many investigators and inventors attempted it with indifferent success twenty and more years ago. There are three basic reasons why such attempts did not meet with success: (1) lack of a suitable electrical transducer; (2) lack of adequate and practical electrical instrumentation; (3) perhaps most important, lack of an insistent demand to meet the needs of the technology of the time. The fact that these three missing factors were completely overcome within the space of a few years accounts for the spectacular advance of electronic load cell weighing that we see going on today in so many diverse fields. %B 16th National Conference, Broadview Hotel, Wichita, Kansas, April 29 - May 2 %I Society of Allied Weight Engineers, Inc. %C Wichita, Kansas %P 56 %8 5/29/57 %G eng %U https://www.sawe.org/papers/0149/buy %9 9. WEIGHING EQUIPMENT %M 0149 %1 Non-Member Price: $28.00; Member Price: $10.00 Members: First 10 product downloads are Free. %2 10.00 %3 28 %4 SAWE0149