SU1661573A1 - Acoustic hydrostatic level - Google Patents

Abstract

The invention relates to the field of measurement technology, in particular, to devices for determining elevations using communicating vessels filled with a homogeneous liquid, and can be used for systematic measurements of sediment of industrial and hydraulic structures. The aim of the invention is to expand the range of measurable elevations. The proposed device is equipped with an amplifier, a driver and an echo pulse fixing unit connected to a signal processing circuit. A screen with an opening is placed inside each vessel at a predetermined distance from two acoustic transducers in such a way as to completely screen the acoustic signal of the first transducer and freely pass the acoustic signal of the second transducer reflected from the surface of the liquid. 2 Il.

Description

The invention relates to a measurement technique, in particular, to devices for determining elevations using communicating vessels filled with a homogeneous liquid, and can be used for systematic measurements of sediments of industrial, hydraulic and other structures,

The purpose of the invention is to expand the measurement range.

Figure 1 shows the block diagram of the level; Fig. 2 is a diagram explaining his work.

Acoustic hydrostatic level contains communicating vessels 1 and 2 with working fluid 3 connected by pipe 4. First acoustic transducers 5 are installed in the front parts of the vessels, at a given distance I from which screens 6 with openings 7 are placed. The recording part of the device contains a synchronizer 8 connected to the first inputs of two identical measuring channels 9 and 10, each of which contains a series-connected generator 11 probe pulses, the output of which through the first outputs measure Channel 9 and 10 are connected to the input of the corresponding first acoustic converter 5, the first amplifier 12, the first driver 13, the first echo pulse fixation unit 14, the delay time measurement unit 15, the counter unit 16, the setup input of which is connected to the synchronizer 8 output, are connected in series 17 survey, the inputs of which are connected to the outputs of the first and second measuring channels and 10, the arithmetic unit 18,

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indicator 19 and generator 20 counting pulses.

Next to the first acoustic transducer 5 from the conical acoustic trap 21 a second acoustic transducer 22 is placed, connected to the output of the probe pulses generator 11 and the input of the second amplifier 23, the output of which is connected through the second shaper 24 and the fixing unit of the time measurement delays.

The acoustic trap 21 is made by a material having a high acoustic viscosity, such as brass. Acoustic transducers 5 and 22 are made, for example, by milling a barium titanium plate pre-glued with a compound on the end of an acoustic trap 21, which ensures that their acoustic characteristics are identical.

In order to completely shield the signal of the first acoustic transducer 5 and freely pass the acoustic signal of the second transducer 22, vessel diameter dc, diameters cH and d2 of acoustic transducers, diameter do 7 holes in screen 6, distance C between transducers, minimum screen width 6 above the transducer 5 and the angle a of the radiation aperture of the transducers are related by the relations:

do d2 + l-sln a.

C 2) -sin a,

b di -and-slna,

do di + d2 + 2bsina.

The angle of the aperture at frequencies of 3-10 MHz, ensuring accuracy of 0.1 to 0.1 mm, for converters from barium tmtanat.

Acoustic hydrostatic level works as follows,

The reference vessel 1 is installed on the structural element at a point with a known absolute elevation, and the measuring vessel 2 is placed at a point, the altitude position of which must be determined. After some time, liquid 3 in vessels 1 and 2, flowing through pipe 4, is set at a certain level, with the distance from the liquid surface to the corresponding acoustic transducers 22 differing by the difference of the elevations of the measuring point and the reference point.

After switching on the device, the synchronizer 8 begins to produce short periodically following electrical pulses, the duty cycle of which is determined by the speed of a particular type of arithmetic unit 18. Each synchronized pulse5 starts the generator of 11 probing and (and setting the pulses to the initial state of blocks 14-16 and 25 each measuring channel 9 i / 10. When each sync pulse arrives, generator 11 produces powerful short pulses that excite the corresponding acoustic transducers Whether 5 and 22, resulting in a liquid surface 3 5 E converter 5 and 22 short ultrasonic pulses are radiated.

The ultrasonic pulse of the transducer 5 is reflected from the screen 6, and the ultrasonic pulse of the transducer 22, 0 freely passes through the opening 7 in the screen 6, from the surface of the working fluid 3. The echo pulses received by the transducers 5 and 22 are transformed into electrical signals and then transmitted through the corresponding amplifiers 12 and 23 to the inputs of the formers 13 and 24. From the outputs of the formers 13 and 24, the pulses go to the fixing blocks 14 and 25, and then to the block 15 of the measurement of the delay time of the first 5 and second pulses 22 The third input of the block 15 receives pulses from the generator 20 counting pulses. From block 15 counting pulses are passed to the corresponding inputs

5 unit 16 during the delay time of echo pulses of the first 5 and second 22 transducers. In block 16, the counters count the counting pulses, the counting results are then recorded in the corresponding registers of block 16 for the echo pulses of each acoustic transducer in a separate register.

Record management in the register is carried out on two buses from 15. After

5, the arrival of the corresponding echo impulse unit 15 generates a prohibition signal for blocks 14 and 25, which prohibit the passage of subsequent echo pulses at the outputs of blocks 14 and 25. Information from each measuring

Channels 9 and 10 from the registers of block 16 in the form of a parallel binary-decimal code are fed to the inputs of the polling block 17, from where they are then entered into the arithmetic unit 18. The counting results are displayed by the indicator 19.

The difference of marks in the reference and measuring points is calculated by the arithmetic unit by the formula

AH - | i-i4-- H- Г115

where And and 2 are the distance of the acoustic transducers to the screens in the first and second vessels;

1 and ti are the delay times of the echo pulse reflected from screen 6 in channels 9 and 10, respectively;

r and t is the delay time of the echo pulse reflected from the surface of the liquid in channels 9 and 10, respectively;

As an arithmetic unit 18 and indicator 19, it is advisable to use a programmable microcalculator, in which the constants I and la and the program of calculations are entered before the measurement. The liquid level from the vessel without loss of accuracy is advisable to be in the range of (1-10) I.

Claims (1)

Invention Formula Acoustic hydrostatic level, containing vessels with acoustic screens and holes in them, partially filled with liquid and interconnected by a liquid pipe, a synchronizer, a generator of counting pulses and a series connected interrogator, an arithmetic unit and an indicator, in the bottom part Each of the vessels houses the first acoustic transducer associated with the corresponding generator of probe pulses and with the corresponding sequentially connected first amplifier, the first rover 1 ;, the first block of fixation of echo pulses. a delay time measurement unit and a sietchik block whose outputs are connected to the corresponding inputs of the polling unit, and the setup input is connected to the synchronizer output connected to the inputs of the probe pulse generator, the first echo pulses fixation unit, and the corresponding delayed input unit with an output of a counting pulse generator, characterized in that, in order to expand the measurement range, it is equipped with conical acoustic traps and series-connected in accordance with the number of vessels acoustic transducers connected to the corresponding probing pulse generators, second amplifiers, second shapers, and second echo impulse fixation blocks associated with the synchronizer output and the corresponding time delay measuring blocks, with a cone acoustic trap installed in each of the vessels between the bottom and the first acoustic transducer, the first and second acoustic transducers are rigidly connected with it, and the hole in the acoustic screen is located above the second acoustic This transducer is made with a cross section that is larger than the second acoustic transducer.