SU919475A1 - Optical device for measuring concentration of nitrogen in atmosphere - Google Patents

Abstract

OPTICAL METER OF NITROGEN DIOXIDE IN THE ATMOSPHERE, containing a radiation source, a corner reflector, a receiving lens, a polychromator and a power supply unit / distinguished by that from a block of light-guides connected in series through a split optical wedge with a balanced comparison circuit.

Description

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The SP Optical Nitrogen Dioxide Meter is designed for use with nitrogen oxides in a polluted atmosphere. Known optical meter kbmventratsii gases in the atmosphere, osmovaky on the method of differential current measurement. In a known device, a three-frequency laser is used as a radiation source. However, when probing at two wavelengths of an op is due to an error associated with the scattering of light in the atmosphere and the generation of fenium by other gases. The closest technical solution is a concentration gauge for gas detectors containing a source of radiation, an angled O | akkatel, receiving lens, for itXfraMaTop and power supply unit. However, it does not provide sufficient measurement accuracy and reproducibility. The aim of the invention is to improve the accuracy and reproducibility of measurements of the concentration of nitrogen dioxide in the atmosphere. This is achieved by the fact that a system for comparing radiation intensities is introduced into the meter that contains the radiation source, the angle reflector, the receiving lens, the polychromator, the power supply unit. a spectrum consisting of a block of light guides connected in series through a calibrated optical wedge. with a balanced comparison circuit. The drawing shows the scheme of the proposed meter. The nitrogen dioxide concentration meter in the atmosphere contains a radiation source 1, a reflector 2, a corner. reflector 3, receiving lens 4, swivel mirror 5, polychromator b, system 7 comparing radiation intensities over the spectrum, containing an optical fiber unit 8, optical wedges 9 calibrated, photomultipliers 10, balanced amplifier 11, The device is also equipped with a power supply unit 12. The device operates as follows. The radiation from source 1 is concentrated by the reflector 2 and directed to the corner reflector 3. The reflector 3 directs the radiation to the receiving lens 4, which focuses the radiation to the INPUT slot of the polychromator 6. The diffraction grating of the polychromator b projects the image of the spectrum onto the input window of the fiber unit 8. The optical fibers 8 collect the radiation from a number of spectral regions into two groups, corresponding to large and small absorption in the gas under study. This radiation is directed to the cathodes of the two PMTs 10, in front of which optical wedges 9 are made of neutral glass. - With one of the wedges 9, the light fluxes are equalized in the absence of absorption by the test gas, which is achieved by switching to a short path using a rotating mirror 5. Equality The PMT currents are recorded by the balanced amplifier 11. The displacement of the second optical wedge 9 until a balance is reached when the probe beam travels along the path under study gives the concentration of the gas to be detected. The use of new elements of a fiber optic module, connected in series with calibrated optical wedges and a balanced comparison circuit, distinguishes the optical gas concentration meter from the indicated prototype in that it has a higher accuracy of measurement results. The device is simple to manufacture, compiled mainly from commercially available zlemento.v, portable, which is convenient for mass measurements.

Claims (1)

OPTICAL METER OF NITROGEN DIOXIDE CONCENTRATION IN ATMOSPHERE A PE containing a radiation source, an angular reflector, a receiving lens, a polychromator, and a power supply unit, characterized in that, in order to increase the accuracy and reproducibility of measurements, it uses a spectrum comparing system of radiation intensities consisting of a block of optical fibers connected in series through calibrated optical wedges with a balanced comparison circuit.