SU1396041A1 - Ultrasonic device for determining the properties of moving medium - Google Patents

Abstract

This invention relates to the measurement of the dynamic properties of moving media by an ultrasonic method. The aim of the invention is to improve the accuracy and enhance the functionality by measuring also the speed of sound. Piezo transducer 1, 2, 3, 4 proton is the test medium in opposite directions. The received pulse-sequences are amplified, converted into digital values. The calculation of the velocities of ultrasound and the movement of the medium is carried out using as. time stamps of the pulse sequence of one of the acoustic channels. At the output of the adder-subtractor 10, the desired values are obtained, and at the output of the adder 14 - the numerical values of the measurement time stamps, 1 sludge. with s

Description

(L

The invention relates to the field of measurements, in particular dynamic measurements of the properties of flows of gases and liquids in pipelines,

The aim of the invention is to improve the accuracy and enhance the functionality by measuring also the speed of ultrasound.

The drawing shows a structural diagram of an ultrasonic device for determining the properties of a moving medium.

The ultrasonic device for determining the properties of the moving medium contains two emitting 1.2 and two receiving 3.4 piezotransducers with the first 5 and second 6 amplifiers connected to them, the outputs of which are connected to the information inputs of the converter 7 time interval - digit, synchronizer 8, connected to the control inputs of amplifiers 5.6 and converter 7, block 9 for calculating return values, connected to two outputs with an adder-subtractor 10, and two inputs with outputs of registers II and 12, a register

13, connected to the output to the adder

14, the second input of which is connected to the output of register 11, the output with converter 15, the digit is the time interval, connected to the control input of register 12 and the second control input of register 11; the resolver: 16 connected to the output of amplifier 6, and you - a stroke with the first control input of the register 11 and the control input of the register 13, and the information outputs of the converter 7 are connected

with the information inputs of registers 11, 12 and 13, and the outputs of the device are the two outputs of the adder-subtractor 10 and the adder 14.

The device works as follows.

On Wednesday, characterized by the speed of ultrasound C and the speed of movement V (t), at times ti T P, where T is the sounding period, is the sequence number of the emitted pulse, piezo transducers 1, 2 send probing signals in opposite directions. Moreover, the duration of the acoustic signal is less than the propagation time l / C, where 1 is the distance between the transmitter 1,2 and the receiver 3.4 piezoelectric transducer

meters, and Wed is the average sound velocity in the medium.

Amplifiers 5.6 probing signals are represented as point signals.

(delta-shaped) pulses arriving at the inputs of the converter 7 time interval - a digital value and a decision block 16,

Thus, at the output of amplifiers 5,6 there are two time series of estimates of the time of passage depending on the time points

(T () (), with

 () T. i tV, (1)

Q

five

0

f - (-). (-) . g- (-) t (t) T 1 -f-t,

i) o (

(2)

where is L; , L i-e pass time

when probing, respectively, in and against the direction of the velocity V (t).

The sequence of start-up pulses of transceivers 5, 6 at times Tn is set using synchronizer 8.

Transducer 7 of the time interval type is a digital value of the time of passage, IL and the emission moments of the signal t T P are converted to digital values, respectively, N

WI- M

with . (+; i-j

Further, the values of N, N, and N. are recorded, respectively, into registers 11, 12, and 13 by a pulse outputted by block 7 after the conversion of the i-x time values to digital ones is completed.

In each i-M probing cycle, decision block 16 operates according to an algorithm that implements the expression,.

B) / / 3) where 6 is the threshold for detecting the initial and final moments of the transition process in the channel formed when sounding against the velocity direction V (t), the Difference determines the subtractor 1b, the value of € is recorded in advance in memory 16a of block 16 , Its value is determined on the basis of a priori information about the smallest value of the velocity V (t). When condition (3) is fulfilled, threshold device 16 accepts the absence hypothesis in the time interval ft.,, T. speed jump V (t),

31396041

Provided, (;, moreover, threshold device 166 accepts the hypothesis of the presence of a velocity jump in the time interval tj,. T,

Provided), moreover, the threshold device 166 accepts the hypothesis of the end of the transition process in

with r; t,

time interval

In the case when sinyl changes its value, pulse shaper 16g emits pulses, the time interval between which characterizes the duration T of the transient process in the channel formed during sounding against the velocity direction V (t). In this case, the imyuls 16g shaper operates according to an algorithm that implements the expression

(- (

 D- "- DG

(four)

moreover, j 1,

(-five

point in time of the end running process; t - the initial time of the transition process:

Thus, at the output of the decision block 16 there is an impulse characterizing the duration and time of the end of the transient process.

-one

begins

At the moment of time, the operation in the mode of counting the contained registers 11 and 13, which are then summed by adder 14, is summed up according to the expression

Nui

+ N.

(five)

The digital value A by converter 15 is converted into a pulse emitted at the time & , and

BUT.

YU

 0

 ()

+ t.

(tr)

Where

- duration of the transient process in the channel formed by probing against the direction of the velocity V (t)

At times fi j, the contents of register .12 are read.

After computational procedures, blocs 9 and 10 implement expressions

(7)

{". (.. ./-IT-

(M (c.)} (,

I- J C (f-1 -) 1

N N;

(eight)

ten

15

50

gg

at the output of the circuit there are two sequences of digital quantities, the speed of ultrasound and the speed of movement of the medium ..

The adder 14 outputs the values of the timestamps Q-.

with

- Thus, in the proposed technical solution, mutual synchronization is carried out in accordance with the time points of the output of the measurement result and the time points of receiving the probe signals when they pass in the direction of the velocity V (t) when the sounding period is. Such measurement procedures contribute to the reduction of the dynamic error, which proves the experimental study carried out using numerical methods.

25

Claims (1)

Invention Formula An ultrasonic device for determining the properties of a moving medium, containing two ji emitting two receivers 30 piezotransducer connected to them, respectively, the first and second amplifiers, the time interval converter is a digit, the synchronizer connected to the control inputs of wuxi, 35 motors and the time slot converter input is a digit, the other two inputs are connected to the amplifier outputs, the block calculating the reciprocals and the sum of the 40 torus-subtractors associated with it, characterized in that, in order to increase the accuracy and enhance the functionality by measuring the ultrasound velocity as well, it is equipped 45 three registers, informational inputs of which are connected to the corresponding-. the time interval is a digit, the decision unit, the input connected to the output of the second amplifier, and the output to the control input of the third register and the first control input of the first register connected in series by an adder, the first input of which is connected to the output of the third register, and the converter the digit is the time interval whose output is associated with the control input of the second register and the second control input -51396041 " the first register, the connected output adder, and the output of the second register house in the first input of the calculating unit is connected to the second input of the calculating unit and the second input of the reciprocal.