SU1341553A1 - Device for determining gas refraction - Google Patents

Abstract

The invention relates to refractometry and can be used to determine the refraction of gases and gas mixtures. The purpose of the invention is to simplify the device, expand the spectral range of measurements and reduce the size. The goal is achieved by using multi-sectional cuvettes in the comparative and working channels, the optimal number of sections of which depends on the choice of window material and non-selective differential optical-acoustic receiver. The cuvette, the working channel, is first filled with a reference gas with a known refraction and the readout is taken. And then it is determined by the gas produced and the readout is taken. The refraction S of the gas to be determined is calculated from a ratio of about 8, a / a ,. 1 il. 00 4 JV ate with

Description

one

The invention relates to refractometry and can be used to determine the refraction of 8 gases and gas mixtures in a wide spectral range.

The aim of the invention is to simplify the device and expand the spectral range of measurements, reducing the size of the device.

The drawing shows the measuring circuit of the device for determining 5.

The device consists of a radiation source 1, off-axis parabolic reflectors 2, modulator 3, zero flap 4, working cell 5, evacuated (comparative) cell 6, non-selective differential optical-acoustic receiver 7 and recording unit 8.

The signal U P receiver 7 is proportional to the difference output Etsih from the cuvette 5 and 6 radiant fluxes

.

where m is the number of sections of the cuvette; n - the refractive index of windows

cuvettes;

t is the transmittance of the material of the windows when the thickness is different total thickness; not these windows;

F is the radiant flux incident on the cuvette.

The root of the equation 9 m 0 which corresponds to the maximum value u9 is the optimal number of sections of the cuvette „„ „2п / (п-) or

Wholesale quantities of internal

2p P 1p-T7

windows defined (2)

For example, when making windows of sodium fluoride, for which n is -1.325 at a wavelength of 0.6 µm, p 24, t, e, with millimeter windows of thickness and the distance between them, the length of the cuvette is 51 mm, which is approximately 20 times less than the length of the cuvette of the interferometer ITR-1, designed

ten

- (-

20

415532

for measuring small S values. Accordingly, the device dimensions are smaller than for an ITR-1 interferometer with a 1000 mm cuvette,

The presence of elements 3.7 and 8 in the measuring circuit of the device allows measurements within the transmission band of the window material, for example, in the case of sodium fluoride in the range of about 0.2 to 7 microns.

The device works as follows.

The cuvettes 5 and 6 are pumped out to the forevacuum, after which the zero reading on the scale of the registration unit 8 is established by means of the zero flap 4. Then the cuvette 5 is filled with a reference gas with a known refraction of 5 c and a lower

waving on the scale of counting a ,,. Next again

The cuvette 5 is pumped out to the forevacuum, after which it is filled with the gas to be detected and the readout is taken. Sign & a ' a and a and S are calculated from 8 Sy a / a.c.

 and ratios

0

0

five

Claims (1)

Invention Formula A device for determining the refraction of gases, containing a radiation source, and along the radiation path, a unit for forming two identical parallel beams of rays, in the path of which there are identical working and comparative cells with optical windows, and a radiation detector connected to the radiation recorder, characterized in that in order to simplify and expand the spectral range of measurements, to reduce the dimensions of the device, the cuvettes contain additional internal windows with a refractive index n, located perpendicular to the direction of radiation, while their number p is determined from the ratio 2n  The radiation detector is designed as a non-selective, differential opto-acoustic receiver. R one, 0