Air humidity dynamic detecting device for intensifying air photoacoustic spectrometry based on quartz tuning fork

Abstract

The invention discloses an air humidity dynamic detecting device for intensifying air photoacoustic spectrometry based on a quartz tuning fork. The air humidity dynamic detecting device for intensifying air photoacoustic spectrometry based on a quartz tuning fork comprises a DFB (distributed feed back) laser device, a modulation current source, a temperature controller, a control cabinet, a power distributor, an arbitrary waveform generator, a lock-in amplifier, a base, a casing pipe, a tail fiber connector, a self-focusing lens, a quartz tuning fork and a computer, wherein the modulation current source and the temperature controller respectively control the injection current and the working temperature of the DFB laser device, so that the output wavelength of the DFB laser device has a stronger water-vapor absorption peak close to 1370nm; the arbitrary waveform generator provides a modulation signal, and modulates the output light frequency of the DFB laser device periodically; after the DFB laser device output light passes through the self-focusing lens, a focal point of the focusing light beam is positioned in a clearance between two arms of the quartz tuning fork; a photoacoustic spectrometry signal generated under the interaction of the detection light of the quartz tuning fork and an absorption gas is amplified by the lock-in amplifier, and is output to a computer; the computer displays the measured air humidity in real time.

Description

technical field [0001] The invention belongs to the technical field of gas sensing devices, in particular to an air humidity dynamic detection device based on a quartz tuning fork enhanced gas photoacoustic spectrum. Background technique [0002] Air humidity is a characterization of the water vapor concentration in the air. Air humidity detection is widely used in meteorological observation, environmental control, drying treatment, plant cultivation, process control and other fields. Traditional humidity measurement methods mainly include "dry-wet bulb" method, "dew point meter" method and "humidity-sensitive capacitor" method. These methods have certain limitations in practical applications: the accuracy of the dry-wet bulb hygrometer is low, And the measurement conditions are relatively harsh; the advantage of the dew point method for measuring humidity is that the accuracy and resolution are very high, but its equilibrium time is long, which is not suitable for dynamic ...

AI Technical Summary

Problems solved by technology

Traditional humidity measurement methods mainly include "dry-wet bulb" method, "dew point meter" method and "humidity-sensitive capacitor" method. These methods have certain limitations in practical applications: the accuracy of the dry-wet bulb hygrometer is low, And the measurement conditions are relatively harsh; the advantage of the dew point method for measuring humidity is that the accuracy and resolution are very high, but its equilibrium time is long, which is not suitable for dynamic humidity measurement; the humidity sensitive capacitance humidity sensor has high sensitivity and is easy to realize miniaturization and integration. but less accurate

But its high cost, complex equipment, bulky, limited application

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