SU1254358A1 - Refractometer - Google Patents

Abstract

The invention relates to the field of analytical instrumentation, in particular, to automatic differential refractometers, and is intended to increase the accuracy of determining small differences in the refractive indices of liquids while maintaining a wide range of measurements. The lens 4 forms the image of the diaphragm 3, made in the form of two slits, in the plane of the edges of the prism 8, made in the form of a rhombus, from the beam splitting edge of which the prism is removed. On the edge of a prism, rays of light are refracted and divided into four, parts. When the aperture is shifted, the ratio of the light fluxes incident on the right and left halves of the photodetector changes. The difference between the light fluxes is proportional to the difference of the refractive indices of ve-. of the substances passing through the cuvette, 2 Il. W with to JV Oiki oo sd 00 0tie.f

Description

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The invention relates to analytical instrumentation., In particular, to automatic differential refractometers, is intended to: Improve the accuracy of determining small differences in the refractive indices of liquids, while maintaining a wide measurement range, and can be used in chemistry, biology, medicine, agriculture, and in all areas of the art where liquid chromatography is used, it is an indispensable detector for analyzing non-absorbing or weakly absorbing ultraviolet visible radiation ue compounds (polymers, hydrocarbons, zh.irnye acids or carbohydrates). .

The purpose of the invention is to increase the threshold sensitivity of a refractometer by increasing the coefficient for converting beam deflections into an electrical signal.

FIG. Figure 1 shows the optical circuit of the refractometer; FIG. 2 shows the passage of light through a prism shown in the horizontal plane.

The refractometer contains a source of radiation - a tungsten lam-pu 1 of incandescence and a condenser 2 located along the radiation path; a diaphragm 3 is installed behind the condenser, projecting lens 4 spaced from the diaphragm to a distance equal to the focal length; , 8 bottom of the Scheme Us. and the zero plate 7, a prism 8, directly behind it is a differential photocurrent of 9.. The device works as follows.

The light beam from the lamp 1 through the condensator 2 and the diaphragm 3 is transmitted to the cuvette 5, the condenser and the projection line 4 for 4 form an image of the filament of the lamp on the mirror 6 since pro 54358 J; .

the exact cuvette is the aperture diaphragm. In addition, the lens 4 is used to form the image of the diaphragm 3 in the plane of the edges of the prism

5 to 8 and to form a parallel beam of light passing through the flow cell 5. The beam of light is reflected from the mirror 6, tilted down, and passes a second time through the flow cell. The zero plate 7 serves to displace the beam when the instrument has a zero line. On the edges of the prism, the light rays are refracted and divided into four parts. When the diaphragm image is shifted, the ratio of the light fluxes incident on the right and left halves of the photodetector changes. The difference in the luminous fluxes is proportional to the difference in the refractive indices of the 20 substances passing through the cuvette.

The signal from the photodetector is fed to the input of the measuring circuit.

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formula of invention

A refractometer containing a radiation source and a condenser located along the radiation, a diaphragm, a projecting lens, a flow cell,

30 mirror, zero plate, prism and differential photodetector, characterized in that, in order to increase the threshold sensitivity of the refractometer by increasing the coefficient of conversion of the deflection of rays into an electrical signal, the diaphragm is made in the form of two slits spaced apart in a horizontal plane, while the width

40 of each of the slits and the distance between them are equal, the prism is made in the form of a rhombus, from the splitting edge of which the prism is similar to it, and the distance between the two formed 45 vertices is equal to the center-to-center distance of the slits of the diaphragm.

Phage.2

Editor V. Koitun

Compiled by S .. Golubev Tehred M. Morgenthal

Order 4712/46

Circulation 778

VNISHI State Committee GCCP

On affairs of inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab, 4/5

Production and printing company, Uzhgorod, st. Project, 4

Proofreader A. Obruchar

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Claims (1)

Claim A refractometer containing a radiation source and a condenser located along the radiation path, a diaphragm projecting a lens, a flow cell, a mirror, a zero plate, a prism and a differential photodetector, characterized in that, in order to increase the threshold sensitivity of the refractometer by increasing the conversion coefficient of the deflection of the rays into electric the signal, the diaphragm is made in the form of two slots spaced in the horizontal plane, while the width of each of the slots and the distance between them are equal, the prism is made in the form a rhombus from which a similar prism has been removed from the beam-splitting rib, and the distance between the two vertices formed is equal to the center-to-center distance of the slits of the diaphragm. FIG. 2