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.