SU1233644A1 - Double-beam gas analyzer - Google Patents

Description

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And the decree relates to analytical instrumentation and can be used to control emissions of industrial enterprises and road transport to the atmosphere, as well as to control technological processes associated with the emission of gases.

The purpose of the invention is to improve the measurement accuracy by eliminating the component error from the redistribution of radiation fluxes through optical channels during the measurement process.

The drawing shows a structure, an urn diagram of a two-beam gas analyzers - a jam.

The dual-beam gas analyzer contains a working channel emitter 1 made in the form of a radiation source 2 and a reflector 3, a reference channel emitter 4 made in the form of a radiation source 5 and a reflector 6, a mirror, 1Y modulator 7, working 8 and reference 9 cuvettes, first 10 and second 11 focusing systems, nepBbrfi 12 and BTopoft 13 optical filters, first 14 and second 15 radiation detectors, electronic processing unit 16, clock generator 17, preamplifier 18, synchronous detectors 19 and 20 of the working and reference channels, respectively, comparing adjustment device 21 and the source 22.

The gas analyzer works as follows.

The radiation from the emitter 1 of the working channel is modulated by the mirror modulator 7 so that in one half-period the radiation flux passes through the hole in the mirror modulator 7, the working cell 8 and is focused by the first focusing system 10 on the receiving platform of the first radiation receiver 14 through the first optical filter 12, and in the other half period, it is reflected from the surface of the mirror modulator 7 and is focused by the second focusing system 1J onto the receiving surface of the second radiation receiver 15 through the second optical filter 13, Radiation 4 from the emitter to a reference channel is modulated in a similar manner. Optical filters 12 and 13 are designed to isolate the wavelength at which the absorption of the mass is investigated (located in the working cell 8. From the output of the first receiver

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Radiation 14 The electrical signal is fed to the input of the electronic processing unit 16, which conducts its processing and registration. From the exit

From the second radiation receiver 15, after amplification in the preamplifier 18, the gt-modulated electric signal is fed to the information inputs of the synchronous detectors 19 and 20 pa.

jO of the boom and reference channels, respectively. In order to control the operation of the sicon detectors 19 and 20, the driver of the clock pulses 17 generates synchronization pulses arriving

J2 on the control, lower the inputs of the synchronous detectors 19 and 20. Thanks to this, at the output of the synchronous detector 19 of the working cock there is a constant voltage, the level of which

20 is proportional to the intensity of the radiation emitter 1 of the working channel, and at the output of the synchronous detector 20 of the reference channel is a constant voltage whose level is proportional25 to the intensity of the radiation emitted by the emitter 4 of the reference channel. The output voltages of the synchronous detectors 19 and 20 are applied to the inputs of the comparison device 21, in which the voltage comparison takes place.

From the output of the comparison device 21, the control signal proportional to the difference of its input voltages is fed to the input of the controlled source feeding the source

3 emissions 5 emitters 4 reference channels. If the radiation intensity of the emitter 1 of the working channel becomes less than the radiation intensity. the emitter 4 of the reference channel, respectively, at the output of the synchronous detector 1U of the working channel, the voltage level will become less than the voltage level at the output of the synchronous detector 20 of the reference channel, and the output of the comparison device 21 will have a difference signal, under the influence of which the output voltage of the adjustable source 22 decreases, which leads to a decrease in intensity

 of the radiation of the radiator 4. If the radiation intensity of the radiator 1 of the working channel becomes greater than the intensity of the radiation of the radiator 4 of the reference channel, then the output of the comparison device 21 causes a difference signal, under the influence of which the output voltage of the adjustable source 22 rises and

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Consequently, the intensity of the radiation emitter 4 of the reference channel increases.

Thus, during the operation of the dual-channel gas analyzer, the radiation intensities of the working and

of the reference channel and, therefore, through the working and reference cell, and this, in turn, lowers the sensitivity threshold of the device, limited by the redistribution of radiation flux through the channels, which allows to increase the accuracy of the Measurements,

Claims (1)

A TWO-BEAM GAS ANALYZER containing a working channel emitter, optically coupled through a mirror modulator placed at an angle to the optical axis, a working cell, a first focusing system and a first optical filter with a first radiation receiver, the output of which is connected to the electronic processing unit, a reference cell, and a sync pulse shaper, connected with a mirror modulator, while the outputs of the generator of the clock pulses are connected to the synchronization inputs of the electronic processing unit, characterized in that, with the aim of increasing the accuracy of measurements by eliminating the component error from the redistribution of radiation fluxes through the optical channels during the measurement process, it additionally contains optically conjugated reference channel emitters, a second focusing system, a second optical filter, a second radiation receiver coupled to the preamplifier, synchronous working and reference channel detectors , a comparative device and an adjustable source, while the emitters of the working and reference channels are optically coupled through the second focusing To the system that receives radiation fluxes reflected from the surface of the mirror modulator g, the preamplifier is connected to the information inputs of synchronous detectors of the working and reference channels, the control inputs of which are connected to the outputs of the clock generator, and the outputs to the inputs of the comparison device, the output of the comparison device through an adjustable source connected to the emitter of the reference channel. S1L ... 1233644