MULTI-FREQUENCY TEMPERATURE MODULATION FOR METAL-OXIDE GAS SENSORS

摘要

This article presents an empirical study of temperature modulation for metal-oxide gas sensors at multiple frequencies ranging from 0.125Hz to 4Hz. Commercial metal-oxide sensors from two manufacturers were exposed to analyte concentrations below their isothermal discrimination threshold over a period of ten days. The results reported in this article indicate that temperature modulation can significantly increase the selectivity of the sensors with respect to isothermal operation, yielding classification rates on test data close to 100%. The effects of heater voltage frequency and drift on the two sensors, as well as drift compensation procedures, are also discussed.