Operation and Calibration Procedures for a Small Four-component Strain Gage Balance

The Florida Technological University four-component strain-gage balance is an internally mounted, half-inch diameter balance capable of measuring four components of load: front and rear normal force, axial force, and rolling moment. Measurement of these components is accomplished by means of sixteen strain gages that are mounted on the balance and wired into four full bridge circuits. When the balance is subjected to a load, the strain gages, through a small resistance change, indicated the strain a balance element is undergoing. This report presents a description of the balance and its support equipment, and outlines specific calibration procedures necessary to their successful implementation. These calibration procedures take two forms: that of calibrating the readout equipment, and that of calibrating the balance itself. Also contained in this report is a method of reducing calibration data into a set of parameters applicable to the balance. To aid in the calibration of the balance, a calibration assembly was designed and built. Two calibration models were designed to facilitate the incremental loading of the balance and the interpretation of the readout data.