Temperature and Humidity Effects on SAW Hydrogen Sensor And Compensation Method

Palladium-nickel (Pd/Ni) thin-film coated surface acoustic wave (SAW) sensor exhibits excellent performance for sensing hydrogen (H ₂ ), but it still suffers from the response drift induced by environment temperature/humidity in practical applications. To enhance the stability and accuracy of SAW sensors, this work demonstrates the effects of temperature and humidity on Pd/Ni alloy thin-film coated SAW sensors and proposes a temperature/humidity compensation method. Pd/Ni-loaded SAW sensor integrated micro-heater is fabricated on Y35°X quartz crystals by photolithographic technique and magnetron sputtering method, and the hydrogen sensing experiments are conducted at different temperature (-25 to 55°C) and humidity (0 to 60%). The results indicate that the baseline and response sensitivity of the sensor are significantly affected by temperature. The interference of humidity is relatively small due to the micro-heater which reduces the adsorption of water molecules on the Pd/Ni film. Further analysis shows that the effect of temperature on the system components is cross-coupled, so an in-situ temperature/humidity compensation method is proposed from the perspective of the system as a whole. By applying this compensation method, the baseline drift induced by temperature/humidity of the system is reduced by 97.86%, and the concentration prediction error is reduced from 22.58% to 4.83%. This demonstrates the effectiveness of the compensation method and provides technical support for the reliable application of SAW sensors in complex environments.