Abstract: Interference signals from other gases in an air sample are eliminated by flowing an air sample directly to an electrochemical gas sensor and subsequently flowing an air sample through a selective scrubber and removing the target gas of interest before flowing the sample to the electrochemical gas sensor. The difference in responses of the electrochemical gas sensor is directly proportional to the concentration of the target gas of interest in the air sample.

Abstract: A gas detection system comprising a gas sensor having a detection surface for detecting an analyte gas, the accuracy of detection being degraded by the presence of an unwanted gas at the sensor, and a thermal scrubber layer directly adjacent said detection surface of the gas sensor defining a diffusion path for the analyte and unwanted gases to traverse through to the detection surface, the diffusion path having a sufficient length and the thermal scrubber being heated by the heater to a sufficient temperature capable of at least partially thermally decomposing the unwanted gas prior to contacting the detection surface to thereby improve the accuracy of the sensor. The system further comprises a heater that is preferably arranged to heat both the detection surface and the thermal scrubber. The invention is particularly useful for improving the performance of an NO2 gas sensor in the presence of ozone (O3).