Monolithic piezoelectric and ferroelectric crystal multifunctional dew point humidity sensor

Abstract

This invention discloses a single disk piezoelectricity electrical transistor multi-function dew-point humidity sensor, which comprises the following: sensor outer shell with Kefa tube shell 1 and Kefa tube socket 8; piezoelectricity transistor sensitive element 6 fixed inside the sensor shell; semi-conductive cooling device 7 of the outer single machine control and outer interface legs of the Kefa tube socket 8. It realizes the cooling and heat feedback control, sensitive characteristics compensation and adjusting signals and conversion, which improve the accuracy, resolution rate and dynamic range and pollution status identification of the sensors.

Description

Technical field: [0001] The present invention relates to a precise and fast response multifunctional piezoelectric and ferroelectric crystal (such as quartz crystal, LiNbO crystal, aluminum phosphate crystal, PZT piezoelectric ceramic, ZnO sapphire piezoelectric film, etc.) Monolithic piezoelectric ferroelectric crystal multifunctional sensor for dew point, frost point, humidity, and temperature in mode elastic wave operation. It uses surface acoustic waves in Rayleigh wave mode to be sensitive to condensation and frost; uses bulk acoustic wave mode or shallow body acoustic wave mode to be sensitive to dew point or point temperature; uses bending vibration mode body wave or torsional vibration mode body wave to be sensitive to ambient temperature; uses semiconductor refrigeration Controller and single-chip computer software and hardware realize cooling / heating feedback control and sensitive characteristic compensation, signal conditioning and conversion, etc. technical backg...

AI Technical Summary

Problems solved by technology

Analog sensors have high requirements on the stability of the power supply, and there is a problem of "thermal drift" or "temperature drift" of the external circuit, so the resolution is low and the accuracy is poor

[0012] 4. The RTD passes through a large current, and there is also a problem of self-heating, and there is a problem of interference with the original temperature field

[0013] 5. It is difficult for the RTD to be set on the dew point on the surface of the sensor, so there is a temperature gradient between the detected "condensation temperature" and the actual dew point temperature. In other words, the temperature measured by the RTD is not the real dew point temperature

[0014] 6. During the transition from dew point to frost point, the sensor has instability problems

[0015] 7. The sensitive element needs to be exposed to the measured environment during dew point measurement, so dust, oil mist, etc. may adhere to the surface of the sensitive element. Although the fog resistance of the optical dew point sensor may be improved a lot, there is still a problem. Issues requiring improved surface contamination resistance, and contamination self-cleaning issues

[0016] 8. Surface wave sensitive components are often in the process of "cooling down" and "heating up", and sometimes even in a state of rapid heating and cooling, which is tantamount to increasing the aging of the sensor

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