SU1303906A1 - Device for determining volume concentration of suspensions in light absorbing media - Google Patents

Abstract

The invention relates to devices for determining the volumetric concentration of suspended particles in media with varying optical density and improves the measurement accuracy by linearizing the dependence of the output signal on the measured parameter in a wide range of concentrations. The device contains a source of light 1, a measuring camera 2, a photodetector 3 of transmitted non-diffused light, a photodetector 4 of light scattered at a certain angle, a unit 5 of summation of signals of photodetectors associated with a unit 6 controlling the intensity of the light flux of the light source. The control unit 6 controls the intensity of the light source 1 so that the sum with certain coefficients of the scattered and transmitted light fluxes is constant regardless of the change in the light absorbing properties of the medium and the concentration of particles. Registering the device 7 with a linear scale is connected to the photodetector of 4 scattered light flux, 1 dw., 1 tab. with b (L with oo with about O)

Description

The invention relates to photoelectric measurements and can be used to measure the content of suspended particles in liquid and gas-bearing media in food, chemical, microbiological and laboratory studies.

The purpose of the invention is to improve the measurement accuracy by linearizing the dependence of the output signal on the particle concentration.

The drawing shows a diagram of the device.,

The device contains a source 1 J5 of light, a measuring chamber 2, a photodetector 3 of an appropriate non-diffused light flux, located along the axis of propagation of the light flux, a photodetector 4 of scattered light, 20 located at an adjustable angle to the axis of propagation of the light flux, connected 5 with unit 6 controlling the intensity of the light source 25 light flux. The recording device 7 is connected to the photodetector 4 of the scattered light flux.

The device works as follows .30

The light flux from the source of light 1 passes through the volume of the measuring chamber 2 with the medium under study. Particles contained in the test medium scatter light. Part of the luminous flux, weakened during the passage

35

3.20-10 1.6010 8.00-10

4.00-10 2.00-10

1, 00 10

, 00-1 about 2,5010

1.25-10

five

through the medium and not scattered by particles, gets to the photodetector 3, and part of the light scattered within a given solid angle gets to the photodetector 4. The electrical signals from the photoreceivers 3 and 4 are summed with certain coefficients in block 5. The mm signal is fed to the input of the block 6 controls the intensity of the luminous flux of the light source, which maintains the sum of the luminous fluxes falling on the photodetectors 3 and 4 constant. The signal from the photodetector 4 is fed to a recording device 7, the readings of which carry information on the concentration of suspensions.

This solution is used in an instrument for measuring the concentration of biological cells in suspension. The table shows the calibration characteristic of the instrument for a series of consecutive twofold dilutions of the erythrocyte suspension, starting with a concentration of 3.20-10 ml.

The dilution of the suspension produced using a volumetric flask accuracy class of 0.1. The output voltage of the device is measured with a B7-23 digital voltmeter.

It follows from the table that the output voltage of the device linearly depends on the cell concentration with an accuracy of ± 1% in the concentration range 2-10 - 2-10 ml-.

2.962 1.594 0.8041

0.3999 0.1963

0.1000

0.0497 0.0246

0,0121

31303906

The use of the device improves the accuracy of measuring the concentration of suspensions in light-absorbing media.

Claims (1)

Invention Formula the output of which is connected to a light source, and a registering device, due to the fact that, in order to increase the measurement accuracy by linearizing the dependence of the output signal on the concentration, a summation unit is inserted into it, the inputs of which are connected to the outputs of the corresponding photodetectors suspension concentrations in light-absorbing media containing a source of un-diffused and scattered light, optically coupled through the outgoing flows, and the output connected to the closure A photo with a photodetector control, the one that registers the transmitted radiation and the scattered device is connected to the output of the photoreceiving light fluxes, the control unit, the name of the scattered light flux. Editor A. Dolinich Compiled by A. Chubakov Tehred M. Khodanich Proofreader L. Pilipenko Order 1300/43 Circulation 777 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 the output of which is connected to a light source, and a registering device, which is related to the fact that, in order to increase the measurement accuracy due to linearization of the dependence of the output signal on the concentration, a summation unit is inserted into it, the inputs of which are connected to the outputs of the corresponding photodetectors of the last unscattered and the scattered light fluxes, and the output is connected to the control unit, and the recording device is connected to the height of the photoreceiver of the scattered light flux.