RU1805337C - Device for determining the dimensions of particles in liquid - Google Patents

Abstract

SUMMARY OF THE INVENTION: the device comprises a scanning element and marks deposited on a transparent wall of the flow chamber. The electronic part of the device further comprises a circuit for extracting the amplitude of the signal of the calibrating mark and a scaling device. The output of the tag signal extraction circuit is connected to an input of a scaling device, the output of which is connected to a reference input of a multi-level threshold device. 3 s.p. 4-ill.

Description

The invention relates to a control and measuring technique and can be used in industry, biology, medicine, meteorology, as well as for controlling the degree of environmental pollution in ecology, etc.

The aim of the invention is to increase the sensitivity and accuracy of measurements, simplify the process and calibration system, expand the calibration range, and simplify the alignment of the device.

Figures 1 and 2 show a block diagram of a device for determining particle size and concentration in a fluid stream; Fig. 3 is a fragment of a channel for flowing a test fluid; figure 4 is a view of the signal at the output of the amplifier.

The device for determining the size and concentration of particles in the fluid flows contains a sequentially located radiation source (laser) 1, a scanning element 2, the input of which is connected to an exciting generator 3, a focusing optical system 4, a channel for the flow of the test fluid 5, a photodetector 6, an amplifier 7 the signal input of which is connected to the photodetector 6, and the output is connected to the signal input of the threshold device 8 and to the input of the amplitude separation circuit of the label signal 9, the output of which is connected either to the control th input radiation source 1 (Figure 1) or the second (the control) input of amplifier 7 to the input 2 and scaler 10 whose output is connected to the reference input of the threshold device 8. Yield

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threshold device 8 is the output of the device (Fig. 1, 2).

A regular sequence of calibration marks 12 located on the scanning line of the beam 13 (Fig. 3) is plotted on the surface of the fluid flow channel 5 in the region of the counting volume 11.

At the output of the amplifier there is a sequence of signals of the following form (Fig. 4): 14 - signal from the edges of the channel for liquid; 15 - pulse signals from particles; 16 is a regular signal from marks.

When the focused beam intersects the particles in the fluid flow, as well as the marks 12 (Fig. 3) on the channel surface, the photodetector 6 generates a pulse from the particles 15 and a signal regular from the marks 16 (Fig. 4), the amplitude of which is determined by the size particles (or labels).

. The complete signal amplified by the amplifier 7 is fed to the input of the circuit for extracting the amplitude of the label signal 9. This circuit can be implemented, for example, in the form of a peak detector, which remembers the amplitude of the label signal at the moment determined by its phase relative to the channel edge. The circuit can also be made in the form of a filter with a resonant frequency fCK

fp - 2p Tech.

where n is the number of regular labels;

fcK is the beam scanning frequency.

With the aid of a scaling device 10 (e.g., a resistive divider), it is possible to select the threshold of the threshold device 8 corresponding to the desired particle size.

The device allows a simple extension of the number of calibrated particle sizes by increasing the number of scalable, scalable and threshold devices.

The use of a scanning element in combination with fixed calibration marks on the walls of the liquid channel allows one to refuse from introducing a special mechanical calibrator, radiation modulator, or introducing calibration particles into the liquid stream, which simplifies the design and increases the reliability of the system.

The introduction of a tag signal extraction circuit into the device and the control of the radiation source with either an amplifier or a threshold device allows for efficient continuous calibration during the measurement process.

FORMULA AND ZOBRETIN

Claims (4)

1. A device for determining particle sizes in a liquid, including a channel for transporting a test medium having at least two transparent opposite walls, a radiation source, an optical system, a photodetector, an amplifier, the input of which is connected to a photodetector, a threshold device, the signal input of which is connected to an amplifier output, and a reference input with a source the reference signal corresponding to the detected particles, the output of the threshold device is the output of the device, and a calibration signal generation system located in front of the photodetector, characterized in that, in order to simplify the measurements and expand the calibration range, a scanning element located between the radiation source and the channel is additionally introduced dl transportation of the test medium, and the source of the reference signal is made in the form of a circuit for extracting the signal amplitude of the calibration mark and a scaling device, the input of the extraction circuit the amplitudes of the mark are connected to the output of the amplifier, and its output is connected to the input of the scaling device, the output of which is connected to the reference input of the multi-level threshold device, and the system for generating calibration signals contains a mark applied to one of the transparent channel walls. 2. A pop-up device due to the fact that the radiation source has a control input, and the output of the label signal amplitude extraction circuit is connected to the control inputs of the amplifier and radiation source, 3. The device according to claims 1 and 2, characterized in that, in order to increase the reliability of the measurement, the mark is made translucent. 4. The device according to claims 1 and 2, with the exception that the mark is made in the form of a regular series of marks. tfFfv I - - - -, AND 43 W Fig. H