A Digital Frequency Humidity Sensor for Measuring Relative Humidity of Gas

Abstract

The invention discloses a digital frequency type humidity sensor for measuring relative humidity of a gas, in order to solve the problem of digitization of the humidity sensor in the prior art. The invention utilizes the characteristic that the serial connection formed by a sensitive electrode and a quartz crystal resonator has a high-sensitivity impedance frequency modulation characteristic to directly convert the change of electrical properties of the sensitive electrode caused by the relative humidity change in a gaseous-phase environment into the oscillation frequency change of the sensor;the oscillation frequency is collected by a frequency counter and sent to a computer for processing; the sensor disclosed by the invention has the characteristics of high sensitivity, digital frequency output, high stability, and the like.

Description

technical field [0001] The invention belongs to the technical field of sensors, in particular to a humidity sensor technology. Background technique [0002] Sensor technology is one of the three pillars of modern information technology. Humidity sensors are widely used in industrial production, chemical industry, environmental monitoring, medical health and scientific experiments. Among the traditional humidity sensors, capacitive and resistive humidity sensors are the most common. At present, this type of humidity sensor can achieve high humidity detection sensitivity and response speed, but its output is analog, which is easily disturbed by the external environment. In the signal processing process, it is also very easy to introduce errors. Compared with analog humidity sensors, digital humidity sensors have significant advantages in ease of use, anti-interference and reliability. Therefore, the development of digital humidity sensors has become one of the key research di...

AI Technical Summary

Problems solved by technology

The humidity sensor has the advantages of digital frequency output and simple structure, but there are also some problems in the humidity sensor, such as the low response sensitivity of the capacitive frequency modulation type humidity sensor based on graphene oxide, and the poor anti-interference ability of the capacitive sensitive parts; and The capacitive frequency-modulated humidity sensor based on perfluorosulfonic acid also has the problems of easy cracking of the sensitive film, poor film consistency, and poor long-term stability, and the overall performance is difficult to meet actual needs.

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