# Low Temperature Effect of Resistance Strain Gauge Based on Double-Layer Composite Film

## TL;DR

A new strain gauge with a double-layer composite film reduces temperature effects, improving measurement accuracy for structural monitoring.

## Contribution

A novel double-layer composite film strain gauge with ultra-near-zero temperature effect and high TCR stability is developed.

## Key findings

- The strain gauge achieves a temperature coefficient of resistance (TCR) of approximately 0.8 ppm/°C.
- The gauge factor is 1.83 with excellent linearity and TCR repeatability.
- The design effectively minimizes temperature interference compared to single-layer strain gauges.

## Abstract

Strain gauges play a crucial role in numerous fields such as bridge and building structural health monitoring. However, traditional strain gauges generate spurious signals due to the temperature effect, which in turn affects their measurement accuracy. Herein, we propose a resistance strain gauge based on a double-layer composite film, which is characterized by an adjustable resistance temperature coefficient (TCR), an ultra-near-zero temperature effect, and good TCR repeatability. It is precisely through the combination of materials with positive and negative TCR, leveraging their opposing temperature resistance characteristics, that a low temperature effect has been achieved. Compared with the single-layer alloy-based strain gauge, the developed strain gauge based on double-layer composite film has greatly reduced sensitivity to temperature interference, and its TCR can be reduced to a ultra-near-zero value, approximately 0.8 ppm/°C, while the stability of TCR is excellent. In addition, the gauge factor of the strain gauge is 1.83, and it maintains excellent linearity. This work fully highlights the potential application value of the developed strain gauge in stress monitoring of bridges and building structures.