RU1407209C - Correlation radiometer - Google Patents

Abstract

The invention relates to techniques for controlling atmospheric pollution, in particular to instruments for measuring the total gas content, and can be used to remotely measure the total gas content in the atmosphere, mainly in industrial flares. The purpose of the invention is to improve the accuracy of measurements. The invention consists in sequentially passing through four working cuvettes located on the disk of a rotating modulator, radiation transmitted through the plume of an industrial enterprise through one optical path normal to the plane of the diaphragm, interference filter and photodetector at the input of the latter. The output signal of the photodetector is processed taking into account the change in brightness of the radiation source, while the change in the degree of radiation polarization at the input of the optical part of the device does not affect the measurement results. The device provides for the construction of a calibration curve at three points with high accuracy. 1 silt

Description

The device (, .gvvo from the technique of coitrozgr5 zneinost 1 etr-yusfer, in particular to instruments for measuring the total gas content, and can be used to remotely measure the total gas content 8 of the atmosphere, mainly in industrial flares The purpose of the invention is to improve the accuracy of measurements.

The drawing shows a functional diagram of a radiometer.

The radiometer contains a modulator, driven by a motor 1. made in the form of a disk 2 with an engine 1 mounted on it, made in the form of a disk 2 with the first 3, second 4, third 5 and fourth 6 working cells, diaphragm 7, first 8 and second 9 calibration cuvettes, interference filter 10, photodetector 11, pre-amplifier 12, first 13, second 14, third 15 and fourth 16 electronic keys, first 17, second 18, third 19 and fourth 20 storage elements, first 21, second 22, third 23 and fourth 24 amplifiers, first the 25th and the second 26th adders, a subtractor 27, a block 28 of the automatic regulation / amplification amplifier (AGC). phase sensor 29 m block of synchronization 30.

The device works weakly5Dim obrdzssm.

Pseudo more powerful at the input of the device. passed through study 4; Blowed fa -: ag; industrial enterprise (not shown), sequentially, when the MSC 2 is rotated by engine 1, it passes through the first 3. First 4, Third 5 and Fourth 6 working cells. The first 3 and second 4 working cells are filled with the same amount of test gas, one third of the working cell 5 is filled with approximately twice the amount of gas G to be studied, and the fourth cell S is empty. The radiation under investigation, limited by the diaphragm 7, is again an interference filter 10, the passband of which corresponds to the absorption band of the gas under investigation (SOa or N02). arrives at the detector photodetector 11. At the output of the photodetector 11, an electric signal S (U) is received, obtained after the light flux passes through one of the device’s working cells, containing a certain amount of the studied gas and. The number of Ui in the first 3, Ua in the second 4, and ultrasound in the third 5. and Un in the fourth working cell is selected so that the equality holds: S (U1) 4S {Uз S (U2) S (Uд).

The electrical signals S (U) from the output of the photodetector 11 were eaten by vf n / ieMUfl in the preamplifier 12, switched by the first 13, second 14. third 15 and fourth 16 electronic keys to the input of the first 17, second 18, third 19 and fourth

20 memory elements, which are controlled by commands from the outputs of the synchronization unit 30 generated from the output signals of the phase sensor 29.

Electrical signals corresponding to the first working cell 3, are fed to the input of the first memory element 17, the second working cell 4 to the input of the second memory 18, the third working cell - 5 - to the input of the third memory element 19, the fourth working cell 6 - to the input of the fourth memory element twenty..

After memorizing in the first 17, second

18, the third 19 and fourth 20 storage elements and amplification of the first 21, second 22, third 23 and fourth 24 amplifiers electrical signals corresponding to the first 3 and second 4 working

cuvettes are summed in the first adder 25, and the corresponding third 5 and fourth 6 working cuvettes are summed in the second adder 26.

The output electrical signal of the second adder 26 is subtracted from the output electrical signal of the first adder 25 in a subtractor 27, from the output electrical signal of which the amount of gas is determined (S02 or N02).

contained in the test flare.

To compensate for changes in the brightness measurement of the radiation source, which is used as

natural sky radiation, it is necessary to change the gain of the pre-amplifier 12 inversely to the change in the brightness of the source. The gain of the preamplifier 12 is changed using the AGC block 28 when passing through the field 1; 1 and the photodetector 11 of the fourth working cell 6. not filled with the test gas;

way. If the magnitude of the luminous flux passing through the fourth working cell 6 increases, then the AGC block 28 reduces the gain of the pre-amplifier 12. otherwise, the AGC block

28 increases the gain of the preamplifier 12. While passing through the field of view of the photodetector 11, the first 3, second 4 and third 5 r) rir-io4vtx cell coefficient 1 | 1 gain factor npe / v 1 |

USI STEPPE 12 but N; rM :: i. ; g-i

Before and after crossing the torch under study, the device is calibrated by sequentially introducing the first 8 and second 9 calibration cuvettes into the field of view and removing from the field of view the photodetector 11, and then the first 8 and second 9 calibration cuvettes simultaneously, while the disk 2 module the torus rotates. In this way, three points are obtained corresponding to a certain electrical signal at the output of the subtractor 27 and the known content of the test gas in the first 8 and second 9 calibration ditches. In this case, the larger the amount of test gas in them, the greater the amplitude of the electrical signal at the output of the device, which will allow the points obtained during the calibration process to accurately draw a calibration curve, which then determines the amount of test gas in the test flare. During the calibration process, the optical part of the device (not shown) is directed to a clear sky portion.

The radiation passing through the studied flare passes through the first 3, second 4, third 5, and fourth 6 working cells along one optical path of the nor

small to the plane of the diaphragm 7, interference filter 10 and photodetectors 11. When changing the degree of polarization of the studied radiation, changes in the intensity of radiation that passed through the first 3. second 4, third 5 and fourth 6 working cells and arriving at the input of photodetector 11 does not occur, and if it does, then equally for all positions of the disk 2.

Thus, eliminating the effect of a change in the degree of polarization of the studied radiation arriving at the optical input of the device on the signal size allows one to increase the accuracy of measurements.

(56) Cryvnak D.A., Burch D.E. Monitoring of pollutant gases in airsraft exhausts by gas-filter correlation methods. American Institute of aeronautics and astro nautics. - paper, No. 76-110, 1976. p.1-10.

Nikolaev A.H. et al. Remote measurement of sulfur dioxide in emissions from pipes of power plants using correlation-type radiometers. - Environmental Pollution Control Issues,. 1981. Ne 6, p. 34, 36.

Claims (1)

The claims A CORRELATION RADIOMETER containing a modulator optically coupled to the first, second, third, and fourth working cells, driven by a motor, a diaphragm, an interference filter, and a photodetector, EXIT, which is connected to the first input of the preamplifier, the input of which is connected to the output an automatic gain control unit, as well as a phase sensor connected to a modulator, the outputs of which are connected to the inputs of the synchronization unit, and the first and second calibration cells, characterized in that. in order to improve measurement accuracy. it additionally contains first, second, third and fourth electronic keys, first, second, third and fourth storage elements, first, second, third and fourth amplifiers, first and second adders and a subtractor, while the output of the preliminary amplifier is connected to the inputs of the first, second, third and fourth electronic keys, the control inputs of which are connected respectively, with the first, second, third and fourth outputs of the synchronization unit, the output of the first key through the first memory element and the first amplifier is connected to the first input of the first adder, the second input of which is through the second amplifier and the second memory the element is connected to the output of the second electronic key, and the output is to the first input of the subtracting device, the output of the third electronic key through the third storage element and the third amplifier is connected to the first input of the second adder, the second input of which is connected with the input of the automatic gain control unit and through the fourth amplifier and fourth storage an element with the output of the fourth electronic key, and the output with the second input of the subtracting device, and the modulator is made in the form of a disk with the first, second, third and fourth mounted on it working ditches so that the light flux from the object being examined alternately passes through the first, second, third and fourth working ditches and is directed normally to the receiving plane of the photodetector. fifteen 27