摘要 |
A method of humidity measurement wherein a humidity responsive element is subjected to the measuring environment and its temperature coefficient is measured. A system operates a sensor element between a first temperature and a second temperature, determining its temperature coefficient, which is then compared to a previously compiled table. The differential measurement thus made automatically corrects for system error originating in equipment drift, cable capacitance change and various aging and slow hysteresis or sensor capacitance variations. In another embodiment, an occasional differential measurement is performed to detect errors in a set of stored curves and update the tables used for single-point humidity measurements, thus obviating the need for protocols involving reference gases or recalibration.
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