RU1783310C - Acoustic level indicator - Google Patents

Description

The invention relates to the field of measuring the level of liquid and granular media, as well as the thickness and diameter of products using ultrasound.

A device is known comprising an acoustic transducer, a receiving-forming unit, a time interval meter and a pulse generator connected via a frequency divider to a synchronizer.

Its disadvantage is that the ratio of the doubled maximum of the positioned distance to the distance between the emitter and the receiver of the synchronizer is limited by the division factor of the frequency divider. This circumstance reduces accuracy over a wide range of changes in the parameters of the medium, since in this case it is necessary to significantly (several times or more) increase the division coefficient of the frequency divider.

The closest in technical essence and the achieved result is an acoustic level gauge containing the connected probe pulse generator and emitter, the main receiver and amplifier connected in series, the first trigger and the first coincidence stage, the frequency divider, the main pulse shaper, the pulse counter, a reversible counter and connected additional a receiver and an amplifier, the probe pulse generator being connected also to the second input of the first trigger.

A disadvantage of the known technical solution is the narrow range of distance measurement due to the formation of a dead zone near the emitter and the main receiver, at which the signal from the emitter does not reach the receiver, as well as reduced measurement accuracy, since a code-voltage converter and a voltage-controlled clock generator limit the measurement error at the level of units and fractions of a percent.

The aim of the invention is to expand the range and increase the accuracy of measurements.

This goal is achieved in that in an acoustic level gauge containing connected probing pulse generator and emitter, a main receiver and amplifier connected in series, a first trigger and a first coincidence stage, a frequency divider, a main pulse shaper, a pulse counter, a reversible counter and connected additional receiver and amplifier moreover, the probe pulse generator

also connected to the second input of the first trigger, according to the invention, the pulse counter is adapted to be summed. In addition to the device

introduced the main detector, an additional detector and a pulse shaper, connected in series between the additional amplifier and the probe pulse generator, a calibration frequency generator, a second coincidence cascade, control, power and memory blocks, a NOT circuit, the first, second, third and fourth circuits of I, shapers front and rear fronts and a second trigger.

In this case, the main detector and pulse shaper are connected in series between the main amplifier and the first trigger, the output of which is connected to the first input of the second coincidence stage, the outputs of the calibration frequency generator and frequency divider, respectively, whose output is also connected to the first input of the first, are connected to the second and third inputs circuit And, with a second input

which is connected to the first output of the control unit, the second output of which is connected to the first input of the third circuit AND and the input of the circuit NOT, the output of which is connected to the first input of the fourth circuit And, the output of the calibration frequency generator is connected to the second input of the first coincidence stage, the output of which is connected to the input of the divider frequency, the output of the second stage of matches is connected to the second inputs

the totalizing counter, the third and fourth circuits AND, the outputs of the third and fourth circuits AND are connected respectively to the third and fourth inputs of the reversing counter, with the first and second inputs of which

the outputs of the memory unit and the driver of the leading edge are connected respectively, to the input of which the output of the first circuit And is connected, also connected to the input of the driver of the trailing edge and the second

the input of the second AND circuit, to the first input of which the output of the second trigger is connected, to the first and second inputs of which the outputs of the trailing edge former and the switching unit are connected, respectively

the output of the second circuit And is connected to the first input of the summing counter, and the emitter and the main receiver are made in the form of rings and are located coaxially, and the additional receiver is made in the form

drive and is coaxial with the emitter. The proposed technical solution, in addition to an extended measurement range, has two to three orders of magnitude higher measurement accuracy, since

contains analog signal transmission circuits in the measuring interval r, the quantity T Т t, which provides a more dense filling of r with pulses with a period T0, the duration of which can reach values of c or less (depending on the selected element base) with stability of the same order. In practice, the measurement error is determined by the identity of the channels of the formation of the time Тг Т1, i.e. conditions of their physical feasibility. At the same time, the expansion of functionality is also achieved by measuring the distance to controlled objects, the level of liquid media when placing the emitter and receiver at the bottom of the tank, and the diameter of the rotating cylindrical parts on lathes while maintaining the capabilities of the prototype - measuring the level of liquid and solid bulk media when placing the emitter and receiver outside of controlled environments.

The invention is illustrated in the drawing, in which Fig. 1 is a block diagram of a device; Fig. 2 is a schematic diagram of a control unit; Fig. 3 is a circuit diagram of a memory unit; figure 4 - timing diagrams of the operation of the device.

The device contains a series-connected probe pulse generator 1, an emitter 2, a main receiver 3, an additional receiver 4, an additional amplifier 5, an additional detector 6, an additional pulse shaper 7, a series-connected main amplifier 6, a main detector 9, a main pulse shaper 10, a first trigger 11, the first coincidence stage 12, the frequency divider 13, the second coincidence stage 14, the fourth I circuit 15, a reverse counter 16, and also the first I circuit 17 connected in series trailing edge equalizer 18, second trigger 19, second I circuit 20, pulse counter 21, serially connected control unit 22, third I circuit 23, as well as 24 HE circuit, leading edge shaper 25, switching unit 26, memory unit 27, generator 28 calibration frequency. The output of the driver 7 is connected to the input of the generator 1. The second input of the counter 21 is connected to the output of the match stage 14, the first input of the counter 21 being the counter inhibit input and its second input being the counter. The second input of the circuit 20 AND is connected to the output of the first circuit 17 AND, and the first input of the first circuit 17 And is connected to the output of the divider 13, the second input of the trigger 11 is connected to the output of the generator 1. The third input of the counter 16 is connected to the output of the circuit 23 AND, the second input of the circuit 23 And is connected to the second input of the circuit And 15, and the first input of the circuit 15 And is connected to the output of the circuit 24 NOT. The input of the driver 25 5 is connected to the output of the And circuit 17, and its output is connected to the second input of the counter 16, the output of the switching unit 26 is connected to the second input of the second trigger 19, the memory unit 27 is connected to the first inputs of the reverse

0 of the counter 16. The first output of the generator 28 is connected to the second input of the second coincidence stage 14, and its second output is connected to the second input of the first coincidence stage 12. The counter 22 is capable of summing. The emitter 2 and the main receiver 3 are made in the form of rings and are arranged axially, and the additional receiver 4 is made in the form of a disk and is aligned with the emitter 2.

0 The device operates as follows.

In the case when the control unit 22 issues on its second output O and on the first output 1 (first mode), the generator 1

5 generates an electric pulse arriving at the emitter 2, which converts it into an acoustic impulse. An acoustic impulse reflected from the surface being detached is received by the main receiver 3 and the additional receiver 4, it passes sequentially through amplifier 5, detector 6, driver 7, pulse from the shaper 7 is fed to the input of the generator 1, which supports

5 mode of autocirculation in the synchro ring.

The acoustic pulse received by the main receiver 3 is converted into an electrical pulse and passes through the amplifier 8 sequentially, the detector 9, the shaper 10, is fed to the first input of the trigger 11. The pulses from the output of the generator 1 are sent to the second input of the trigger 11. The pulses from the output of the trigger 11 arrive at the first input of cascade 14. Pulses of calbbrovoin

5 frequencies generated by the generator 28 are fed to the second input of the cascade 12.

The measuring interval g at the output of the divider 13 (diagram Ui3 in figure 5) will be

fifty

g T0

where from

55

T

Then

g (1-T) T0.K4

t + t-t

G () -To K,

hence

t + t

G To Kd- (; p-),

where T0 is the pulse repetition period from the output of the generator 28;

T is the propagation time of the acoustic pulse from the emitter 2 to the main receiver 3;

T 1 is the propagation time of the acoustic pulse from the main receiver 3 to the additional receiver 4;

Cd is the divisor of the divider 13.

The number of pulses transmitted from the second output of the generator 28 through blocks 14.15 to the input of the counter 16 for the interval r is

f

N - t t-

™ - ° G T 4-TL

: That CdTo

T + T

t + t t

tt

1 | /, T / 4-t L T

after multiplying by C the numerator and denominator, we have

N K, K - | t, Cd - K N,

Where

- coefficient:

N distance from the emitter to

location surface;

C is the speed of ultrasound in the medium;

I is the distance between the primary and secondary receivers;

 distance traveled by an acoustic pulse from the emitter to the main receiver.

In the case when the control unit 22 outputs at its second output 1, and at the first output, and all the switches of the memory unit 27 are open (second mode), the distance from the plane of the emitter 2 to the controlled surface is the largest, and the device operates as follows . All bits of the counter 21 at the moment of switching on the instrument are reset. At the moment of switching on the device from the output of block 13, a low level potential is applied to the first input of block 17, therefore, at the output of block 17 there is also a low level potential that goes to the second input of block 20. As a result, the low level potential goes to the first input from block 20 the input of the counter 21 and prohibits its operation. At the moment of switching on, block 26 generates a pulse, which is supplied to the second input of block 19, as a result of which

5

0

5

0

5

0

5

0

5

0

5

a high level potential appears at its output.

At time 11 (Fig. 4), an output potential appears at the output of block 13, which, through blocks 17.20, is supplied to the first input of the counter 21 and to the input of block 25. From the output of block 25, the pulse corresponding to the leading edge of the resolution pulse (in time ti, Fig. 4), is supplied to the second input of the counter 16, as a result of which information from the information inputs of this counter passes to its outputs. At the same time, pulses from the first output of the generator 28 through block 14 are fed to the second input of the counter 21, in which the pulse counting begins. The fourth input of the counter 16 through the block 15 also receives pulses from the output of the block 14, and the counter 16 operates in a subtractive mode. At time i (Fig. 4), at the output of block 13, a low-level potential appears, through block 17 this potential passes to the inputs of blocks 18 and 20, as a result of which a low-level potential appears at the output of block 20, which prohibits summing pulses at the counter 21, at the output of block 18, a pulse arrives at the first input of the second trigger 19, as a result of which the output of the second trigger 19 shows a low level potential applied to the first input of block 20 for the entire duration of the device. At time t, the pulse counting in the counter 21 stops, on the information board of which the indicators light up (go out), indicating the presence (absence) of high potential at the outputs of the counter 21.

In the third mode of operation of the device, the switches of block 27 are manually shorted to the ground against which the non-illuminating indicators of the counter 21 are located. Then the device operates similarly to the second mode with the only difference being that the distance from the emitter 2 to the reference surface should correspond to the real distance to of the control object, and with the occurrence of the enabling pulse (at time ta in Fig. 4) at the output of block 13, this pulse appears at the output of block 17, as a result of which a pulse arriving at the output of block 25 and the second input of the counter 16. At the same time there is a census information output unit 27 through the information input unit 16 outputs this block. At the same time, pulses from the output of block 14 through block 15 are fed to the fourth input of the counter 16, which starts to work in a subtractive mode. At time 14

(Fig. 4) the subtraction of pulses in the counter 16 is stopped and until the time moment m, the indicators of the counter 16 display a measurement result equal to

N2 l i-l2 k2H2,

where № is the number of pulses transmitted to the second input of the counter 21 in the second mode of operation of the device (from time ti to t2 - figure 4);

AN is the number of pulses that are subtracted from the counter 13 in the third mode of operation of the device (from time t3 to time to t4 - Fig. 4);

h is the distance traveled by the acoustic pulses from the emitter 2 to the main receiver 3 in the second mode of operation of the device (in alignment mode);

2 - the distance traveled by an acoustic pulse from the emitter 2 to the main receiver 3 in the third mode of operation of the device (in the measurement mode);

II

H2 1 2 is the distance from the positioned surface to the alignment surface (for example, the liquid level in the tank when located at the top).

When measuring, for example, the diameter of a rotating part on lathes, the value On m - g, i.e. ka (proportionality coefficient), depending on the measurement object, can take values 1 or 2 by choosing the value of Cd.

From the diagram it follows that cascade 12 should have inverse logic compared to cascade 14 (i.e., the signal at the output of cascade 12 should appear when there are zeros at its inputs, and the signal at the output of cascade 14 should have ones at its inputs )

Or (with equally positive logic of blocks 12 and 14), signals from the other output of block 11 should be fed to the input of block 12, i.e. inverted, which is easy to implement, since block 11 means a trigger with separate inputs, which, as a rule, has two outputs (direct and inverse).

Thus, the proposed device allows you to measure:

-distance to controlled objects or the level of liquid media when placing the emitter and receiver at the bottom of the tank (mode 1);

-level of liquid and solid media when placing the emitter and receiver outside the controlled environments (modes 2 and 3 - similar to the capabilities of the prototype);

- diameters of rotating cylindrical parts on turning steaks (mode 2 and 3 with a magnification of 2 times).

Claims (2)

SUMMARY OF THE INVENTION 51. An acoustic level gauge comprising a connected probe pulse generator and an emitter, a main receiver and amplifier, a first trigger and a first cascade of coincidences, a frequency divider, a main pulse shaper, a pulse counter, a reversible counter and connected additional receiver and amplifier, moreover a probe pulse generator 5 is also connected to the second input of the first trigger, characterized in that, in order to expand the range and increase the accuracy of measurements, the pulse counter is configured to be summed, in 0 device additionally introduced main detector, additional detector and pulse shaper, connected in series between the additional amplifier and the probe generator 5 pulses, a calibration frequency generator, a second cascade of coincidences, control, power and memory blocks, a NOT circuit, the first, second, third and fourth circuits and, front and rear edge shapers and a second trigger, while the main detector and pulse shaper are turned on sequentially between the main amplifier and the first trigger, the output of which is connected to the first input of the second 5 cascade of matches, to the second and third inputs of which the outputs of the calibration frequency generator and the frequency divider are connected, the output of which is also connected to the first input of the first 0 of the AND circuit, with the second input of which the first output of the control unit is connected, the second output of which is connected to the first input of the third And circuit and the input of the circuit NOT, the output of which is connected to the first input of the fourth AND circuit, the output of the calibration frequency generator is connected to the second input of the first stage matches, the output of which is connected to the input of the frequency divider, the output of the second stage of matches is connected 0 to the second inputs of the totalizing counter, the third and fourth circuits AND, the outputs of the third and fourth circuits AND are connected respectively to the third and fourth inputs of the reversing counter, with the first and second 5 inputs of which are connected respectively to the outputs of the memory unit and the front edge driver, to the input of which the output of the first AND circuit is connected, also connected to the input of the rear edge driver and the second input of the second AND circuit, the first input of which the output of the second trigger is connected to, the outputs of the trailing edge former and the switching unit, respectively, are connected to the first and second inputs of which the output of the second circuit And is connected to the first input of the summing counter. 2. The level gauge according to claim 1. characterized in that the emitter and the main receiver are made in the form of rings and are located coaxially, and the additional receiver is made in the form of a disk and is located coaxially with the emitter. FIG. 2 FI, ....., -, .-- „PTC.