Driving Strain-Gauge Bridge Sensors with Signal-Conditioning ICs

Strain-gauge sensors - reliable, repeatable, and precise - are used extensively in manufacturing, process control, and the research industries. They transduce (convert) strain into an electrical signal for use in pressure sensors, weight measurements, force and torque measurements, and materials analysis. A strain gauge is simply a resistor, whose value varies with strain in the material to which it is bonded. The article covers the MAX1452 sensor signal conditioner for temperature compensation. The MAX1452's flexible approach to bridge excitation gives the user a substantial amount of design freedom. This article has focused on voltage drive with and without a current boost, but many other bridge-drive configurations can be implemented. Other design considerations include the use of external temperature sensors on the control loop, and achieving sensor linearization (i.e., nonlinearity with respect to the measured parameter) by feeding the OUT signal into this loop.