Piezoelectric strain gage temperature compensation with NTC

LTspice simulation of Full Bridge Piezoelectric Resistive Strain Gage Sensors with Vishay NTC Thermistor/ Resistor Network Compensation

A simple spice model of such gage was found at the following URL:

(PDF) A SPICE model of piezoresistive strain gages using engineering parameters for signal conditioning circuits design (researchgate.net)

This spice model is scalable to all resistive piezoelectric sensors by adapting Resistance, TCR( temperature coefficient of resistance), GF (gage factor) and (TCGF) temperature coefficient of gage factor. The next lines are a snippet of the beginning of the subckt netlist (available as an appendix to thios project)

*Simple Model for Piezoresistive Straingages *The subcircuit straingage simulates the behavior of a straingage * input controls (1 microstrain = 1 microvolt) * Output: floating impedance (pseudo-component) * / \ / \.SUBCKT straingage 1 2 8 9 params: R0=1000, TCGF=-2.0E-3, TCR=1e-3 GF0=100

So it is now possible to place a full piezoresistive bridge into a bias circuit where the bridge voltage will be tuned to compensate nearly exactly the output in a constant way in function of the temperature

By choosing the most appropriate one among the different possible VIshay thermistors and sweeping the values of the resistors of the the compensation network, it's possible to stabilize the bridge voltage for a given strain.