A Dual Electrode Mixed Potential SO₂ Sensor With Humidity Self-Correction Function Utilizing Multiple Linear Regression Model

Gas sensors have been widely used for environmental gas monitoring in many fields. However, the change of ambient humidity will cause deviation in gas concentration measurement. Moreover, the accurate and stable detection of SO2 has been recognized as a challenging problem due to the complex nature of SO2and its harsh detection environment. In this letter, a SO2 sensor based on YSZ solid electrolyte achieving ambient humidity self-correction function was fabricated. Humidity electrode, sensing electrode and reference electrode were integrated on the two sides of a YSZ substrate for the first time. A Pt heater based on Al2O3 plate was utilized to realize self-heating supply. The sensor can detect SO2 of 1–100 ppm in 30% RH–90% RH operating environment. Additionally, a multiple linear regression model was proposed to amend the effect of varying ambient humidity. Our fabricated SO2 gas sensor exhibited its prospect for practical application.