SU1689795A1 - Device for liquid density measurements - Google Patents

Abstract

The invention relates to a measurement technique, specifically to devices intended for measuring the density of a liquid in a wide range of pressures and various geographic conditions. The goal is to increase the measurement accuracy in a given pressure range and when the acceleration of a free fall changes. Into the device containing the measuring float with the balancing element and the transducer of the output signal, a compensation weight insulated from the liquid by the evacuated body is introduced with its own balancing element and transducer of the position into the output signal, pressure sensor, functional pressure transducer, multiplier, subtractor, divider and recorder. The operation of the device provides improved measurement accuracy. 2 Il.

Description

sl C

The invention relates to a measurement technique, more specifically to devices designed to measure the density of a liquid in a wide range of pressures and various geographic conditions.

The aim of the invention is to improve the measurement accuracy in a predetermined pressure range and with changing acceleration of free fall,

Figure 1 shows a diagram of the device; figure 2 - diagram of the computing unit.

The device comprises a float 1 with an equilibration element 2 and a 3 position transducer into an output signal,

sealed enclosure 4, inside of which a compensation weight 5 with an equilibration element 6 and a transducer 7 is placed into an output signal, the output of the transducer 3 is connected to the first input of the subtractor 8 of the computing unit 9, and the output of the transducer 7 - with the first input of the multiplier 10 9, the output of the pressure sensor 11 is connected to the input of the functional pressure converter 12, the output of which is connected to the first input of the divider 13 of the computing unit 9, the output of the setter 14 is connected to the second input of the mind Knife 10, the output of which is connected to the second inlet

vj Yu sp

Subtractor House 8, the output of which is connected to the second input of the divider 13, connected to the input of the recorder 15.

The operation of the device can be explained by the following mathematical expressions.

There is no doubt that

Fi + Vi / Gadget mig, F2 0129. (1)

where FI and Pz are the balancing forces of the float and the compensating load proportional to the displacement;

g is the acceleration of free fall;

ggi and ta are the masses of the float and the compensation load;

Vi is the float volume (current);

/ Water density water (to be measured).

Then

FI

(2)

Since the volume of the float Vi due to reduction varies, Vi Vi (P), where P is the pressure.

For small loads, Vi (P) Vi - e. P, where E is the bulk modulus of the float material.

Then

/Gadfly

m, sf,

vi (P7

ABOUT)

Unit 14 generates a value equal to - - const.

GP2

When the device is placed at the measuring point, the following occurs.

A change in the value of the vertical component of the acceleration of free fall leads to a change in the equilibrium conditions of the compensation load 5, which changes the output signal of the transducer 7 of the position into the output signal. The pressure sensor 11 and the pressure function transducer 12 form the true value of the volume of the float 1. A new value of the output signal of the converter 3 is associated with a change in the balancing conditions of the float 1 by the balancing element 2 due to a change in the density of the liquid (measured), the volume of the float 1 (pressure reduction) and changes in the acceleration of free fall. The output signals of the converters 3, 7, and 12 are fed to the first inputs of the subtractor 8, the multiplier 10, and the divider 13 of the computing unit 9, respectively. The latter, based on the data of the mentioned blocks, as well as taking into account the constant supplied by the transmitter 14 to the input of the multiplier 10, converts them into the value of the density of the liquid rvol.

To compensate for the change in the acceleration of free fall, a signal is used that is received by the system of elements — body 4, compensation weight 5, balance element 6, and converter 7;

pressure reduction is based on the use of sensor 11 and converter 12. The density of the liquid from the output of the computing unit 9 is fed to the recorder 15, where the result is recorded

calculations from block 9. The multiplier 10 over- multiplies the signal of the setting device 14 and the converter 7 of the position, the output signal of the multiplier 10 is fed to the input of the decremented subtractor 8, to the input of the deductible served

the signal from the converter 3, the output of the splitter 13 is connected to the output of the pressure converter 12, the output to the input of the recorder 15. Computing unit 9, realizing the formula (3), calculates the value

fluid density in a wide range of pressures and accelerations of gravity. The result is recorded at the recorder 15 (for example, a self-recording voltmeter).

An implementation option of the Converter 12 may be the following.

The signal from the sensor 11 is in the form of a frequency fed to the input of a series-parallel register, where it is converted into a parallel code, the register outputs are connected to the inputs of a permanent storage device (ROM). An experimental dependence of the float volume on pressure is recorded in the ROM. Thus, the pressure change changes the frequency at the output of the sensor 11, the ROM input code changes and a new float volume value appears at the ROM output.

The device allows maintaining the accuracy of measuring the density of a liquid in a wide range of pressures and with a change in the acceleration of free fall.

5 formula of the invention

A device for measuring the density of a liquid, containing a float, a recorder that is connected to the transducer via a balancing element

float in the output signal, characterized in that, in order to improve the measurement accuracy in a given pressure range and when changing the free fall acceleration, an additional balancing element is added to the device, an additional float position transducer to the output signal, compensation weight, pressure sensor, functional pressure transducer, multiplier, divider, subtractor, sensor, as well as a vacuum-sealed vacuum case isolated from liquid, inside of which are arranged in series Connections compensation load additional elementuravnoveshiFig .1

0

five

The van is connected to the input of the additional transducer of the position of the float into the output signal, while the output of the transducer of the position of the float to the output signal is connected to the first input of the subtractor, the output of the additional transducer of the position of the float to the output signal is connected to the first input of the multiplier, the output of the pressure sensor is connected via a pressure transducer with the first input of the divider, the setpoint output is connected to the second input of the multiplier, the output of which is connected to the second input of the subtractor, the output to orogo connected to the second input of the divider, which is connected to the output of a recorder.

15

H

F, V, (p)

FIG. 2

Claims (1)

Formula of the invention A device for measuring the density of a liquid containing a float, a recorder that is connected through a balancing element to a converter for positioning the float into an output signal, characterized in that, in order to increase the accuracy of measurement in a given pressure range and when the acceleration of gravity changes, an additional element is introduced into the device balancing, additional converter of the position of the float to the output signal, compensation load, pressure sensor, functional pressure transmitter, multiply e, divider, subtractor, setter, as well as a vacuum-tight sealed housing, inside of which there is a series-connected compensation load, an additional balancing element connected to the input of the additional transducer of the float position to the output signal, while the output of the float position transducer to the output signal connected to the first input of the subtractor, the output of the additional converter of the position of the float in the output signal is connected to the first input of the multiplier, you the stroke of the pressure sensor is connected through a functional pressure transducer to the first input of the divider, the output of the setter is connected to the second input of the multiplier, the output of which is connected to the second input of the subtractor, the output of which is connected to the second input of the divider, the output of which is connected to the recorder.