Study on Temperature Modulation Techniques for Micro Gas Sensors

摘要

Gas sensor's sensitivity and selectivity are not only related with sensing material, but also related with its operating temperature. Applying this property, temperature modulation technique has been proposed to improve the gas sensors' selectivity. With a newly developed alumina based micro gas sensor, the sensitivity to CO and CH4 at different operating temperatures are investigated. By modulating the sensor's temperature at pulse and sine wave modes with different frequencies and'amplitudes, the sensor's dynamic responses are measured and processed. Results show that the modulating waveshape plays an important role in the improvement of selectivity, while the influence of frequency is small at the suitable sampling frequency in the range of 25-200mHz.