LT4538B - A ultrasonic meter for a measuring of liquid level - Google Patents

Abstract

This invention belongs to the field of measuring devices, it may be used for automatic observation of liquid medium level parameters in technological tanks and mains and for the relevant measurement thereof. The ultrasonic liquid level gauge consists of a tank (1) with measurement medium (2), in which there is a ultrasonic converter (8), receiver (11), transmitter (16), generator (15), time parameter pulse measurement block (12) and indicator (14); in addition, it has an elastic cover (3) with a fastening cap (4) in its upper part; the cover (3) has a porous limiter (6) inside filled with liquid (5) of equal density to the measuring medium; it also consists of a second ultrasonic converter (9), in a fixed distance from which there is a reflection plate (7) fastened to the limiter (6), commutation device (10), connected to ultrasonic converters (8,9) and transmitter (16), microprocessor block (13), which is connected to a commutation device (10), time parameter pulse block (12), generator (15) and indicator (14).

Description

The invention relates to the field of measuring devices, in particular, it can be used for automatic monitoring of the liquid level parameters of technological tanks and pipelines, as well as for the measurement thereof.

An ultrasonic liquid level transducer is known in which a piezo-ceramic element converts an electrical impulse into an acoustic signal, which passes through a tread made of vacuum rubber and a metal membrane transmitted to the side of the fluid being measured, and into a silicon organic rubber completely suppressed. The metal membrane during radiation protects the sensor's internal cavity from external influences, and at the same time vibrates the acoustic impulse to the liquid side. The diaphragm vibrations are not transmitted to the sensor body and the clamping ring as it is trapped between insulating plates patent no.

2037143.GOI F 23/28, Bul. No.16.1995)

There is known a fluid level measuring device consisting of a step of discretizing the level of a tube-shaped acoustic duct having a cavity made in steps along the tube. On the underside of the tube is a receiving-emitting device connected to a probing pulse generator and an electrical measuring circuit consisting of an amplifier-transformer, a delay line, a valve, a pulse counter, a trigger and an amplitude selector (see USSR Auth. No. 560144, GOI F 23 / 28,1991).

The liquid level measurement device as in analog _u is the lack of that over time. the measured medium changes its properties, produces a sediment that suppresses the acoustic signal and therefore cannot accurately and reliably measure the level of the measured medium.

The object of the invention is to increase accuracy and, at the same time, reliability.

It is an object of the present invention to provide a newly introduced elastic enclosure with an attachment cap on an ultrasonic liquid level gauge consisting of a container containing a measuring medium containing an ultrasonic transducer, receiver, transmitter, generator, pulse timing unit and indicator. fluid of equal density with measuring medium and perforated stopper, second ultrasonic transducer, fixed reflector plate at fixed distance from it, commutator coupled to ultrasonic transducers and transmitter, microprocessor block coupled to commutator block, are indicators.

Because the density of the medium to be measured and the fluid inside the elastic enclosure are the same, the elastic enclosure with the fluid contained in it is deformed with minimal resistance while maintaining the level of the medium, so that the acoustic signal is not suppressed. , will not change with the properties of the medium being measured (eg contamination). It will be reliable and accurate.The perforated stop on the inside of the elastic body prevents deformation of the elastic hood and the holes in it allow the fluid to freely disperse. The top cover of the elastic hood protects the fluid from contamination and stabilizes the hood. a reflector plate at the aperture limiter and a microprocessor processing unit for received signals significantly increases the accuracy and reliability of the meter.

Figure 1 is a block diagram of an ultrasonic liquid meter.

The ultrasonic level gauge consists of a container 1 with a measuring medium 2 containing an elastic enclosure 3 with a sealing cap 4. An elastic enclosure 3 filled with a liquid 5 having a density equal to that of the measured medium 2 and an internally mounted stopper 6 with holes in its walls reflector plate /. Two ultrasonic transducers 8,9 are mounted on the bottom of the elastic enclosure which are connected to the switch 10, the latter in its output through a receiver ^ 11, a time measurement unit 12, a microprocessor block _t 13 connected to an indicator 14. The second input of the switch 10 generator 15 and transmitter 16 are connected to microprocessor unit 13 and a third is directly connected to microprocessor unit 13, the second output of which is connected to indicator 14.

The ultrasonic level meter works as follows.

The microprocessor unit 13 supplies a control signal to a switch 10 which connects the ultrasonic transducer 3 to the receiver 11 and the transmitter 16. The microprocessor unit 13 then excites a generator 15 whose signal is transmitted to the ultrasonic transducer 8 via the LT 4538 B transmitter 16 and the switch 10. and excites an acoustic wave propagated by the fluid 5, reflected from its surface and returned to the ultrasonic transducer 8. From the ultrasonic transducer 8, a signal is transmitted through a switch 10 to a receiver 11, from which it is fed to a time measurement unit 12, and transmitting to microprocessor unit 13 and indicator 14. Thereafter, the microprocessor unit 13 supplies a control signal to a switch 10 which connects the ultrasonic transducer 9 to receiver 11 and s; transmitter 16. The microprocessor unit 13 excites a generator 15 whose signal through transmitter 16 and switch 10 enters the ultrasonic converter 9, excited The acoustic wave propagated by the fluid 5 is reflected from the plate 7 and returns to the ultrasonic transducer 9. From the ultrasonic transducer 9, it passes through a switch 10 to a receiver 11, which is fed to a time measurement unit 12, which measures the time interval T2. a microprocessor unit 13 and an indicator 14 which indicates the water level L:

T1

L = Lp! ------,

T2

Lpl is the distance from ultrasonic transducer 9 to plate 7.

Compared to the prototype, the new set of structural elements allows the measurement of the level of the liquid medium, regardless of its changing properties, thus increasing the accuracy and reliability of the device.

Claims (1)

DEFINITION OF INVENTION Ultrasonic liquid level gauge consisting of a container with a measuring medium containing the ultrasonic transducer, receiver, transmitter, generator, pulse timing unit and indicator, characterized by a newly introduced elastic enclosure with an attachment cap at its upper end filled with a uniform density with a measuring medium and a hole-limiter inside it, a second ultrasonic transducer, fixed at a fixed distance to the hole-limiting reflector plate, a switch connected to the ultrasonic transducers and transmitter, a microprocessor block connected to the switch, a timing unit.