SU1348657A1 - Device for meausuring level of electrically conducting liquid - Google Patents

Abstract

The invention relates to the field of instrumentation and can be used to measure the level of an electrically conductive liquid. The aim of the invention is to improve the accuracy and speed of the device. To achieve this goal, a device containing a drum and a conductive cord wound on it with a load at the end, a brake mechanism, a contact brush, a readout device, a pulley, a power source, a switch mounted on a support, a perforated disk fixed on the pulley, and the reading device contains a light emitter, a photodetector, a unit for setting constants consisting of a counter, a button and an auto-oscillator, an amplifier, a current-limiting element, a differentiating element, a trigger, a reversible counter to, decoder, display unit, control unit. When the load is in the upper position, the switch is closed in the first position, the elements of the control unit are set to the zero state. When the button is pressed by the operator through the task block of constants, the reversible counter is reset to the initial state, which is indicated in the display unit. When the load moves downward, the pulley rotates, with it a perforated disk, and pulses arrive at the input of the reversible counter. When the load reaches the surface of the liquid, the circuit closes: ground - load - conductive cord, contact brush, reading device. The counting of pulses by a reversible counter is stopped and the measurement result is displayed in the display unit. 3 hp f-ly, 2 ill. from W (L from 4 00 o: ate vj

Description

The invention relates to construction and can be used to measure the level of an electrically conductive fluid in gauges with a bore-hole.

The aim of the invention is to improve the accuracy and speed of the device.

FIG. 1 is a block diagram of a device for measuring the level of an electrically conductive liquid; Fig. 2 is a diagram of the reference device.

The device contains a reading device 1, a load 2, a pulley 3 and a drum 4 on which the conductor cord 5 is located, the contact brush 6, the brake mechanism 7, is made in the form of an electromagnet with a winding 8, spiced with a blue spring 9, on which 10 brake pad I1, power supply 12, common bus 13, positive pole 14 of the power supply, make contact 15 switching

body 16, break contact 17 of switch 16, stop 18, emitter 19, photodetector 20, perforated disk 21, amplifier 22, current-limiting elements on resistors 23, block 24 specifying constants, button 25, autogenerator 26, counter 27, a reversible counter 28, a differentiating element 29 consisting of a resistor 30 and a capacitor 31, a trigger 32, a control unit 33, comprising triggers 34 and 35, resistors 23 and an inverting amplifier 36, a decoder 37 and a display unit 38.

A device for measuring the level of electrically conductive liquid works as follows.

Before starting work, the load 2 is raised to the stop 18. The closing contact 1 of the switch 16 is closed. A control pulse arrives at the input of the reading device 1, which sets the triggers 34 and 35 and through the differentiating element 29 triggers 32 to the zero state, and the reversible counter 28 to the through transfer mode.

Before starting the measurement, the counter 27 pulses ycTpopicTBa 1 using the button 25 and the oscillator 26, the operator sets the number of pulses corresponding to the value of Id. The distance from the stop 18 to the ground level minus the length of the load 2 is constant and does not change with subsequent measurements of FIG. one .

five

0

0 5

0

50

five

In the case of installation of a device for measuring the level of an electrically conductive fluid in the channel I ,, - the distance to the ground level, i.e. to the bottom of the channel (figure 1). This is carried out as follows. The operator presses the control button 25. The self-oscillator 26 receives power and starts producing impulses arriving at the input of the counter 27. The code of the number of pulses from the outputs of the latter through the reversible counter 28 arrives at the information inputs of the decoder 37, and the number of impulses of the auto-oscillator 26 is indicated on the display unit 38. (or H) the operator releases the button 25, the autogenerator 26 and the counter 27 stop, keeping the code of the number H (H) until the next intervention of the operator. This state is original. It should be emphasized that the reversible counter 28 is prepared for operation in the subtraction, since at its input the counting direction from the output of the flip-flop 32 a signal O is sent. The count of the number of pulses, and hence the angle of rotation of the perforated disc 21, is started by the reversing counter 28 the control pulse arriving at the control input of the number of the counter 28 from the closing contact 15 of the switch 16 at the beginning of the movement of the load 2 down, since it opens in this case, i.e. the beginning of the counting coincides with the beginning of the movement of the load 2. In this case, the trigger 35 of the device 1 is set to the state of eliminating contact bounce of the switch 16, the enable signal of the end-to-end transfer of counter 28 is removed and the pulse count is enabled, and the signal l from the output of the trigger 35 presets the reversible counter 28 to state no.

The perforated disk 21, rotating, periodically interrupts the luminous flux from the light emitter 19 to the photodetector 20. The latter changes its electrical resistance depending on the luminous flux, causing a corresponding change in voltage at the input of the amplifier 22, which amplifies these voltage pulses and supplies them to Counting 1 input of the reversible counter 28, subtracting their number from the preset value (HL value

properties and 1 11

3

When the number of pulses reaches H, a zero appears at the first outputs of the reversible counter 28, and at the second output a pulse sets the trigger 32 into a single state, which leads to a reversal of the count by a reversing counter 28 when the perforated disk 21 moves in the same direction . Therefore, the subsequent pulses add up, starting with zero.

.The end of the counting of pulses is carried out along the leading edge of the signal O, which arrives at the third input of the counting device 1 from the output of the contact brush 6, as the circuit closes the common 13 - ground - water - load 2 - conductive cord 5 - drum 4 - brush 6. Simultaneously, the brake mechanism is activated. 7. This signal is amplified and inverted by inverting amplifier 36 and sets trigger 34 to state I. In this case trigger 36 is eliminated by a 25 photodetector, a reversible counter.

The contact bounce and gates decoder 37, which decrypts the output code of the reversible counter 28 and outputs it to the display unit 38.

Thus, the measurement was made (figure 2):

H,

H

- N

where H is the distance from ground level

to the water level, m; distance from stop 18 to

liquid level minus load length 2, i.e. measured distance, m. Since the number of pulses recorded by the decoder 37 after the reverse of the counting by the reversible counter 28, corresponds to the distance N.

In the case of installing a device for measuring the level of an electrically conductive fluid in the channel H, the distance to the ground level, i.e. to the bottom of the channel. The counting reverse does not occur, since the code O does not appear at the first outputs of the reversible counter 28 and the pulse at its second output. The reversible counter 28 is always in the subtraction mode. Therefore, the calculation is made according to the formula

H. K „H

AND)"

Those. measured water level H, in the channel.

Accuracy and speed of measurement increases because using Q

3486574

electronic, i.e. instantaneous stop of the counting of pulses, when reaching the boundary of the measured area.

Claims (4)

1. A device for measuring the level of an electrically conducting fluid, containing a power source, a drum on which a conductive cord with a load at the other end is fixed at one end, a braking mechanism, a reading device, characterized in that, in order to improve the accuracy and speed of the device, A scraper rigidly connected to a perforated disk is inserted into it, a contact brush, a limit switch mounted on the support, a conductive cord is placed on the pulley, and the reading device contains a unit for specifying constants, an optical transmitter aka connected through a perforated disk with 0 five control unit, decoder, display unit, current limiting element, amplifier, trigger, differentiating element, the negative pole of the power source is connected to the common bus, and the positive is connected to the brake input, the first output of the switch, the first output of the task unit constants and the first input of the control unit; the output of the brake mechanism is connected to the output of the contact brush and the second input of the control unit, whose third input Q is connected to the second output of the switch l, and the first and second outputs are connected to the control inputs of the decoder and the reversible counter, respectively, the third output of the switch is connected to the input of the setting of the end-to-end transfer of the reversible counter, the fourth input of the control unit and through the differentiating element to the first trigger input, the output of which is connected to the direction input the counter of the reversible counter, the output of which is connected to the second trigger input, the output of the photodetector is connected to the second output of the current-limiting element and the input of the amplifier, od which is connected to the counting input of down counter, a group of inputs of which is connected with the band specifying unit outputs constants, and five 0 five the output group is connected to the information inputs of the decoder, the outputs of which are connected to the inputs of the display unit. 2. The device according to claim 1, characterized in that the brake mechanism is designed in the form of a winding, the terminals of which are the input and output of the brake mechanism and inside which the measles are located, at one end of which the brake shoe is fixed, and the other end through the spring connected to the support. 3. The device according to claim 1, wherein the control unit comprises two triggers, an inverting amplifier and three current-limiting elements, the first output of the first current-limiting element is the first input of the control unit, and the second is connected to the input of the inverting amplifier and is the second input of the unit, the output of the inverting amplifier is connected to the first input of the first the second input is the fourth input of the block and the output is the first output of the block, the second input of the first trigger is connected to the first output of the second current-limiting element and the first input of the second trigger whose output is the second output of the block and the second input is the third the input of the unit and is connected to the first output of the third current-limiting element; the second outputs of the second and third current-limiting elements are connected to the common bus. 4. The device according to claim 1, characterized in that the block for setting constants contains a button, an auto-oscillator and a counter, one pin of the button is the input of the block, and the second is connected to the input of an auto-oscillator whose output is connected to the input of the counter whose outputs are the outputs of the block . (put./ ////// VT / T / P C2 25 Editor E. Kopcha Compiled by M.Sidorova Tehred M.Hodanich Order 5180/40 Circulation 693 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Design, And ig.2 Proofreader V. But ha