Pressure and distance measurements under temperature interference by using impedance change of spiral conductive polymer composite

To realize the compressive-pressure and non-contacting-distance measurements in the curved-interlayer-structure of modern-industrial-equipment under temperature-interference, the influences of temperature on the impedance-variations of the spiral conductive polymer composite (which possesses the tunneling-effect-based-conduction, the intrinsically-flexibility and the ability to induce eddy-current-effect) caused by the pressure and distance are studied. The pressure/distance-impedance-property repeatability increases with the increment of experimental-times, and the pressure/distance-impedance-characteristic is monotonically decreasing/increasing. When the temperature increases from 10 °C to 40 °C, the normalized-impedance-amplitude attenuates/increases and the normalized-impedance-angle raises/decreases under the same pressure/distance, and the sensitivities for the pressure/distance-impedance-property increases. The measurement system based on the two-levels-interpolation is developed and tested under temperature-interference. The testing-results show that the pressure-measurement-error is 8 % F.S. (0–0.65 MPa) and the distance-measurement-error is 5 % F.S. (0–2 mm). The results lay the foundation on revealing the distance/pressure/temperature-sensing-mechanisms of spiral composite, and verify the feasibility of using the spiral composite to measure the pressure/distance under different temperatures.