SU112605A1 - Device for counting and distributing aerosol particles to their sizes - Google Patents

Description

The subject matter of the invention is a device for counting and distributing aerosol particles according to their size, intended for laboratory research of industrial aerosols.

Separate blocks of the described device (electron microscope, transmission camera, electron beam tube, etc.) are known. The present invention provides a set of these blocks, allowing you to automatize the counting of the number of particles and their sizes, and also makes it possible to establish precisely defined intervals of measured particle sizes, which creates a new positive effect.

The principle of operation of ycTpoiicTBa is that an aerosol snapshot obtained using an electron microcon from the iroba is projected onto the input of a television transmitting camera, from which it passes the electronic counting sorting circuit to the visual observation block of the particle distribution graph.

Pa drawing shows a block diagram of ycTpoiicTBa.

A snapshot / aerosol with the help of an optical device 2 is projected onto the input of a transmitting television camera 3. When using a movie television camera with a scanning of B of 625 lines and shooting a frame of size 25X36; the distance between two consecutive lines is 0.04 lgg; the minimum particle size, which can be traced, is 0.03-0.05 m.h. Each larger particle corresponds to the intersection of several lines.

The impulse from the television camera, after passing the block of suppression of false impulses 4, falls on the impulse sorting unit 5, built on a coincidence circuit, at the output of which a pulse of a certain duration corresponding to a certain spot diameter of the aerosol particle appears in the picture.

The pulses from the sorting unit arrive at the counting device 6, which consists of separate counters, corresponding to definite 1M particle size intervals in the photographs.

The counting results are determined directly from the meter readings.

From each counter, the signal is automatically fed to the cathode ray tube of the device 7 for visual observation of the graph of particle distribution. A voltage proportional to the particle size is applied to the vertically deflecting plates of the tube, and a voltage proportional to

the number of particles, resulting in what is on the screen of the tube, a graph of the distribution of the number of particles over

sizes.

Subject invention

Claims (3)

1. A device for calculating the distribution of aerosol particles by their sizes, using images obtained by an electron microscope, characterized in that, in order to automate the calculation of the number of particles by their sizes, a transmission television camera, a sorting unit and a counting unit are used. 2. The device according to claim 1, characterized in that, in order to be able to take photographs and visual observations, a cathode ray tube is used. 3. The device according to paragraphs. 1 and 2, in order to suppress spurious pulses, an interference suppression unit has been applied.