SU1278594A1 - Device for measuring liquid level - Google Patents

Abstract

The invention relates to instrument engineering and allows for improved measurement accuracy. When the liquid level in the pipe 2 reaches the reference point a, the output of the detector 5 turns on the logical O and, through the control unit 7, the pressure unit P recorded by the pressure converter 9 is recorded in the memory unit 13; neither When the liquid level in the pipe 2 decreases to the reference point b, the logic signal O also appears at the output of the alarm 6 and, through the control unit 7, the pressure value PJ in the tube 2 corresponding to the level of the fluid in it of the reference point S is recorded to memory 12. The memory blocks 12 and 13 of the value of Pj, and PJ are fed to the signal processing unit 14, where the value of the measured liquid level is calculated. 1 il. Air HchE "szdo sd C0

Description

1, on reaching logical unit

one

The invention relates to instrumentation, namely piezometric level meters, and can be used in various fields of industry to measure the level of liquid media in 1 tanks.

The purpose of the invention is to increase the measurement accuracy by eliminating, on the measurement result, the specific gravity of the fluid,

The drawing shows the proposed device.

A device for measuring the level of liquid in the tank 1 contains a piezometric tube 2, inside which sensors 3 and 4 of the liquid level detectors 5 and 6, the control unit 7, the electropneumatic valve 8, the pressure pressure converter 9. are installed, inside the uh. , choke 11, memory blocks 12 and 13, and signal processing block 14.

The device works as follows.

In the de-energized state, the electric pneumatic valve 8 ,. turns on the supply of the filter 10 through the throttle And into the piezometric tube 2, then the fluid is pushed out of it and the level in it is lowered, the passage of reference points a,. When voltage is applied to the electropneumatic valve 8, it is actuated, thereby shutting off the air supply from the line through the filter 10 and connects the cavity of the tube 2 to the atmosphere through the throttle 11..

When power is applied to the level measurement device (after air supply), the signals of the logic O. are set at the outputs of the level sensors 5 and 6.

At the same time, the output signal of the block

7 controls on electropneumatic valve

8 is energized, which interrupts the air supply and connects the cavity of the tube 2 with the atmosphere. After this, the liquid of the tank 1 begins to fill the tube 2 and the level of the liquid in it begins to rise. When the liquid level in the tube 2 reaches the sensor 4, a Doric level appears at the output of the level indicator 6.

sensor levels 3

also occurs at the output of the detector 5. As a result, the unit 7 pack

five

0

five

after a set delay time, the electropneumatic valve B is de-energized, air from the line begins to flow through filter 10, valve 8 and throttle 11 into the cavity of tube 2, the level of which begins to decrease.

When the liquid level in the tube 2 reaches the reference point o. and the liquid ceases to omit the sensor 3, a logical O appears at the output of the detector 5 and through the control unit 7 into the memory unit 13 is recorded. the pressure value P measured by the pressure transducer 9 at the moment of reaching the liquid level in the tube 2 of the reference point a. Meanwhile, the liquid level in the tube 2 continues to drop. When this level decreases to the reference point S and the fluid stops washing sensor 4, logical O also appears at the output of the detector 6 and, through control unit 7, memory value 12 records the pressure in tube 2 corresponding to

in it is a reference point S. WITH

fluid block outputs

12 and 13 memory

pressures P, and P enter

signal processing unit 14, where, in terms of H, P4ih / P | -P calculates the value of the measured liquid level.

When the liquid level in the tube becomes lower than both sensors 3 and 4, the control unit 7 is supplied with electric power to the electropneumatic valve 8 through the set delay time, which operates and closes the compressed air supply to the tube 2 and connects its cavity with the atmosphere. The fluid level in tube 2 begins to rise and the cycle described is repeated.

Thus, in a piezometric tube 2, level fluctuations constantly occur, i.e. moving it down below sensor 4 and then up above sensor 3. At these positions, the solenoid 8 is activated and de-energized and the measurement cycle is repeated.

55

Claims (1)

1 The invention relates to instrumentation, namely piezometric level meters, and can be used in various industries to measure the level of liquid media in 1 tanks. The purpose of the invention is to increase the accuracy of measurement by excluding, on the basis of the measurement result, the specific gravity of the liquid. The drawing shows the proposed device. A device for measuring the level of liquid in the tank 1 contains a piezo-metric tube 2, inside which sensors 3 and 4 of the liquid level detectors 5 and 6 are installed at a distance uh, a control unit 7, an elec- tropneumus valve 8, an pressure signal converter 9. electric signal 10, throttle 11, memory blocks 12 and 13, and signal processing block 14. The device works as follows. In the de-energized state, the electric pneumatic valve 8 ,. includes the supply of air: and from the filter 10 through the throttle And into the piezometric tube 2, while the liquid is pushed out of it and the level in it is lowered, the passage of the reference points a,. When a voltage is applied to the electropneumatic valve 8, it triggers, thereby shutting off the air supply from the line through the filter 10 and connects the cavity of the tube 2 to the atmosphere through the throttle 11.. When power is applied to the level measurement device (after air supply), the signals of the signaling devices 5 and 6 are set up by the signal. After this, the liquid-1 of the container 1 begins to fill the tube 2 and the level of the liquid in it begins to rise. When the liquid level in the tube 2 reaches the sensor 4, in the course of the indicator of the 6 level indicator 1, the logical level of the sensor 3 is reached. A logical unit also appears at the output of the indicator 5. As a result, the control unit 7 de-energizes the electropneumatic valve B, the air from the main begins to flow through the filter 10, the valve 8 and the throttle 11 into the cavity of the tube 2, the level in which begins to decrease. When the liquid level in the tube 2 reaches the reference point o. and the liquid ceases to omit the sensor 3, a logical O appears at the output of the detector 5 and through the control unit 7 into the memory unit 13 is recorded. the pressure value P measured by the pressure transducer 9 at the moment of reaching the liquid level in the tube 2 of the reference point a. Meanwhile, the liquid level in the tube 2 continues to drop. When this level decreases to the reference point S and the fluid stops washing the sensor 4, logical O also appears at the output of the warning device 6 and through the control unit 7 the pressure value in the tube 2 corresponding to the level of the reference point S is recorded in the memory unit 12 . Fluids 12 and 13 of memory of pressure outputs P and P flow into block 14, where, in the expression H, P4ih / P | -P calculates the value of the measured liquid level. When the liquid level in the tube becomes lower than both sensors 3 and 4, the control unit 7, after a set delay time, supplies power to the electropneumatic valve 8, which operates and closes the compressed air supply to the tube 2 and connects its cavity to the atmosphere. The fluid level in tube 2 begins to rise and the cycle described is repeated. Thus, in a piezometric tube 2, level fluctuations constantly occur, i.e. moving it down below sensor 4 and then up above sensor 3. At these positions, the solenoid 8 is activated and de-energized and the measurement cycle is repeated. Apparatus of the Invention A device for measuring the level of a liquid, comprising a piezometric tube, located at one end into a liquid, and a level indicator sensor located therein, the other end of the tube is connected to an outlet of an electropneumatic valve and a pressure transducer, while the input of an electropneumatic valve is connected to a source of compressed air, and its second An outlet with an atmosphere, characterized in that, in order to improve the measurement accuracy, a control unit is introduced into it, the second level detector, the sensor of which is also installed in the piezometric tube, two memory blocks, a signal processing unit, while the outputs of the first and second level detectors are connected to the first and second inputs of the control unit, the first output of which is connected to the control input of the electropneumatic valve, the second and third outputs of the control unit are connected with the control inputs of the first and second memory blocks, respectively, the information inputs of which are connected to the output of the pressure converter; the outputs of the first and second memory blocks are connected respectively to the first and second inputs signal processing unit, the third input of which is connected to the fourth output of the control unit.