Shunt Calibration for Dummies – a Reference Guide

Shunt calibration is a technique for simulating strain in a piezo-resistive strain gage Wheatstone bridge circuit by shunting one leg of the bridge. The bridge may be internal to a discreet transducer or composed of separately applied strain gages. The resulting bridge output is useful for calibrating or scaling instrumentation. Such instrumentation includes digital indicators, amplifiers, signal conditioners, A/D converters, PLC’s, and data acquisition equipment. Care must be taken to understand the circuits and connections, including extension cables, in order to avoid measurement errors. Shunt cal is the means of calibrating or verifying instrumentation by simulating a physical input. The simulation is accomplished by shunting one leg of a Wheatstone bridge circuit. Not a means of calibrating a transducer. It is considered the “poor mans” simulator.