SU1117484A1 - Density meter - Google Patents

Abstract

A PLOTNOMER containing a measuring chamber, a recorder and a maximum and minimum pressure generation unit, the output of which is connected to the recorder input and the measuring chamber, characterized in that, in order to improve accuracy and improve the presentation of information, it contains a repeater with a shift, linear resistance and a generator rectangular pulses, the output of which is connected to a linear resistance control input, whose information input is connected to the output of the repeater with a shift, and the output c from measuring camera and the entrance of the repeater with a shift. With s

Description

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This invention relates to instrumentation, namely, to measuring the density of liquid media.

Known densitometer, containing the measuring chamber, unit pneumopulses and the recorder. The principle of operation of the densitometer is to periodically supply air into the measuring chamber to displace fluid from it and discharge air to the atmosphere when the chamber reaches the specified values, and the density is determined by the frequency of the pneumo pulses L,

The disadvantage of this device is the poorly perceived form of the representation of the measurement result.

 The closest to the invention in its technical nature is a densitometer comprising a measuring chamber, a recorder and a maximum and minimum pressure generation unit, the output of which is connected to the recorder input and the measuring chamber zj.

The disadvantages of the known device are insufficient measurement accuracy and poorly perceived form of information presentation.

The purpose of the invention is to demonstrate measurement accuracy and shape improvement.

submission of information. I

The goal is achieved

The fact that a densitometer containing a measuring chamber, a recorder and a maximum and minimum pressure generation unit, the output of which is connected to the input of the recorder and the measuring chamber, further comprises a repeater with a shift, a linear resistance and a generator of rectangular pulses, the output of which is connected to the control input of the linear resistance, the information input of which is connected to the output of the repeater with a shift, and you - with the measuring chamber and the input of the repeater with a shift.

The drawing shows the scheme of the proposed densitometer.

Density meter includes measuring chamber 1, recorder 2, maximum and minimum pressure forming unit 3, including a reference element 4, maximum and minimum pressure setting devices 5 and 6, inductors 7, normally closed valve 8, check valve 9,

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power capacity 10, node 11 of the line of increasing pressure, containing (in turn, the generator 12 square-wave pulses, the repeater 13 5 with a shift, the linear resistance 14 and the choke 15.

The density meter works in the following way.

In the initial state, the pressure in

10, the measuring chamber 1 is equal to the minimum formed by the minimum pressure setting unit 6. This pressure is supplied to the input of the repeater 13 with a shift adjusted to a positive shift. Upon receipt of 12 rectangular pulses from the generator, linear resistance begins to work, at the output of which linearly increasing

20 pressure. At the moment when the pressure in the measuring chamber reaches the maximum maximum pressure determined by the setting device 5, the reference element 4 is triggered, the channel of the measuring chamber is connected through the valve 8 to the output of the minimum pressure setting 6, and the pressure in the measuring chamber drops to the minimum. In this way

30, a cyclical process of filling and emptying the chamber with gas with a constant pressure differential occurs. The change in pressure in the measuring chamber 1 is recorded by the recorder 2. In this case, the rate of change of pressure (the angle of inclination of the straight line) depends on the density of the liquid. The relationship between the density and the rate of increase in pressure can be derived from the equation of the filling dynamics of the measuring chamber.

When air is supplied to the chamber, its mass changes by

lgr |.-5H,

where is the gas density;

5 - the cross-sectional area of the chamber; H is the amount of fluid movement in the measuring chamber.

From the equality of air pressure in the chamber to the hydrostatic pressure of the fluid at the beginning and end of its movement

P, (,,

where P, Pj pressure lower and higher boundaries; 3 h - difference between the level in the vessel under study and the initial level of the bone in the chamber}. Рd is the gas pressure in the vessel under study. Find the difference between P- and P, P, -P, .pg () 4p.p | h-Pe,, or H -.- P2-P,. P Substitute the value in the equation for LM-L, g iW p Flow through a pulsating core is linear: am where b is the time of filling the measuring chamber with gas. (V5 Р, -Р, Pg t-From here l .q Р Р г г J 2 i Р are constant, т о Рг5 where К Ч From the last expression it is seen that the density of fluid D is proportional to the rate of increase of gas pressure in the measuring chamber and not depends on the liquid level.The proposed device allows more accurate (due to more accurate measurement of the density of the solutions) to control the processes of obtaining the initial solutions and ultimately to produce the output of chemical reactions with a lower content of impurities.The economic effect occurs when using the proposed lottery meters in process control systems where the preparation of solutions of a given density is required.

Claims (1)

A DENSITY METER containing a measuring chamber, a recorder and a unit for generating maximum and minimum pressure, the output of which is connected to the input of the recorder and a measuring chamber, characterized in that, in order to increase accuracy and improve the presentation of information, it contains a repeater with a shift, linear resistance and a rectangular pulse generator, the output of which is connected to the control input of the linear resistance, the information input of which is connected to the output of the repeater with a shift, and measure the output noy camera and the input of the repeater shift. 4* Q0 4 ^>