Fast solid state gas sensor characterization technique

We describe a new technique for characterizing fast solid state planar gas sensors. Using a moving gas outlet, we are able to change the gas around the sensor from one component to the next within one millisecond in a step-like manner. By simultaneously sampling at 10kHz, 100Hz and 1Hz, we can capture the fast component of the sensor response as well as the steady state value in a single experiment. The rate of exchange of the gas around the sensor was quantified using laser induced fluorescence (LIF) imaging. The sensor is characterized under standard industrial sensor operating conditions, including gas pressure and device temperature, while using flows typically found in a research laboratory. Since fast response times from planar gas sensors usually require elevated temperatures, we can heat the device to 630 /spl deg/C.