Abstract

This article presents a broad overview of weighing technologies used in traditional industrial, retail, and laboratory weighing applications, and in proportioning and processing of bulk materials. Basic weighing technologies are discussed, including mechanical, hydraulic, analogue, and digital strain-gauge load cells, electromagnetic force compensation, and nuclear. Scale performance is discussed, along with the requirements for commercial scales. Factors that affect weighing accuracy are discussed, including variations in gravity, moisture content, temperature, and influences resulting from buoyancy and electrostatic or magnetic disturbances. The most important industrial, retail, and laboratory scales and balances are described. Various weighing methodologies are discussed, including weighing predefined quantities, controlling package weight, continuous weighing and controlling, and material proportioning. Some typical weighing applications are discussed to illustrate the range of scale functionality presently available. Tank and hopper scale design considerations are discussed, including weigh modules, tension and compression arrangements, weigh module capacity, mechanical considerations, scale calibration, feeding and discharge equipment, and indicators and controllers.