SU1434245A1 - Ultrasonic echo-pulse thickness gauge - Google Patents

Abstract

The invention relates to non-destructive testing, in particular, to means of ultrasonic thickness gauging used in mechanical engineering, aeronautics, power engineering, and other industries of the national economy. The aim of the invention is to increase the measurement accuracy and the control performance by introducing an automatic zero setting of the measurement range and the correction signal. Automatic zero setting is provided by means of an adjustment sample, the thickness of which is chosen to be numerically equal to the value of the speed of ultrasound propagation in it. The measurement process is divided into three stages: in the first, the propagation speed of ultrasound in the material is entered, in the second, the correction factor is automatically calculated and stored, and in the third, the thickness of the test sample is measured, the digital scale is started automatically or manually. measurements. 1 hp f-ly, 1 ill. (L

Description

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The invention relates to a non-destructive testing technique, namely, to ultrasonic measuring tools used in mechanical engineering, aeronautics, power engineering and other industries of the national economy.

The purpose of the invention is to improve measurement accuracy and control performance by introducing automatic zero-setting, measurement zone and correction signal.

The drawing presents a functional diagram of an ultrasonic echo pulse pulse meter,

The ultrasonic echo puller thickness 1number contains a synchronizer 1 connected in series, an excitation pulse generator, an ultrasonic transducer 3 with an adjustment sample 4j amplifier 5, shaper 6 pulse impulse / laser former switch 1S first circuit I 8, first counter 9, The second counter 10 connected in series, the first register 11 of the memory, the decoder. 12 and digital indicator 13 ,. an electronic circuit 14 of the delay, connected to the output of the generator 2 of the excitation pulses J by the second input to the second output of the driver 6, is measured. Pulses are output to the second input of amplifier 5, the code of the generator 2 of the excitation pulses is connected to the second input of the generator 6 measuring pulsesg the generator of 15 calibration pulses, the input and connected to the second and third outputs of the synchronizer 1j and the output to the second of the first switch 7, the generator 16 counting pulses, the output connected to the second input of the first cxer-ju AND 8 ,, shaper 17 starting pulses, the input connected to the third output of synchronizer 1 and the second inputs of the decoder 12 and digital about the generator 13s, the first output to the third input of the imaging unit 6 measuring pulses, the second output to the second input of the first counter 9 and the first input of the second counter 10, the former 18 rewriting pulses, the first input connected to the third output of the synchronizer 1, the output to the second input of the first register 11 memory, and the third input to the output of the first switch 75 is a switch 19, the input connected to the output of the driver 19 pulses

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rewriting, serially connected first electronic key 20, second memory register 21, third counter 22, output connected to the first input of multiplexer 23, second input connected to the common bus, and output to the second input of the second counter 10, output connected to the second input of the second memory register 21, the first input of the first electronic key 20 is connected to the output of the driver. 18 rewriting pulses, the second input connected to the second output of the imager 17 starting pulses, the second electronic switch 24J output connected to the second input of the third counter 22, the first input to the second output of the imager 17 starting pulses, the second switch 25, output connected to the third input of the second counter 10 , the first and second inputs to the first and second outputs of the first counter 9, the third switch 26, the first input connected to the second output of the first counter 9, and the output to the input of the driver 27 signals correction, the first and second outputs connected respectively to the third and fourth inputs of the third counter 22, the first, second and third outputs of the switch 19 are connected to the third, fourth and fifth inputs of the first 7 and second 25 switches, the second inputs of the first 20 and second 24 electronic keys are connected respectively to the first and second outputs of the switch 19, the second input of the third switch 26 is connected to the second fy output of the switch 19, the third output connected to the input of the control circuit 28, the first and second outputs of the switch constant respectively to third and fourth inputs of multiplexer 23.

Shaper 27 correction signals contains a serially connected first shaper 29 single pulses, shaper 30 delayed pulses, the second circuit And 31 and the scheme OR 33, the second input connected to the output of the second shaper 33 single pulses. The output of the first shaper 29 single: pulses connected to the second input of the second circuit AND 31 is the first output of the shaper 27 of the correction signals. Exit and third

The input of the OR 32 circuit is the second output and the input of the correction signal 27 generator, respectively. Ultrasonic echo-pulse thickness gauge works in three modes:

I mode — enter the value of the C velocity of ultrasound propagation in the material;

II mode - automatic calculation and storage of the correction value;

III mode - thickness measurement, automatic and manual correction of the beginning of the digital scale of the measurement range.

Modes I and II are used when performing the operations of adjusting the end and the beginning of the digital scale of the range of measurment. The switching of the modes is carried out by the signal 1 coming from the outputs 1, 2 and 3 of the switch 19.

In the first mode, switch 19 is set to first position. In this case, at its first output, level 1 is present at level O at the second and third outputs.

At the beginning of the measuring cycle, the TOBbJM station with a pulse coming from the outputs of the former 17 sets the initializer 6 to the measuring pulse and zeroes the first 9 and second 10 counters. In this case, the second counter 10 is zeroed out through a multiplexer 23 open for passing through it a level O arriving at its third input from the first output of signal control circuit 28 1, which is generated when operating in modes I and II

From the signals from output 2 and 3 of synchronizer 1, the reference pulse driver 15 generates calibration pulses of stable duration, which arrive at the second in of the first switch 7. Signal 1 comes from output 1 of switch 19 to input 3 of the first switch 7. At the same time, the calibration the pulses are passed by the first switch 7 to the first input of the first circuit AND 8, opening it for counting pulses from the generator 16 counting pulses to the second input of the first circuit 8. 8. The generator 16 counting pulses operates asynchronously elations to fronts measuring pulses following the output of the first switch 7. Counting pulses passed by the first AND circuit 8 for time dei

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The measurements of the measuring pulse (1 measurement cycle) are received from the last output to the first input of the first counter 9, which performs the function of the frequency divider. The third input of the second switch 25 receives a signal 1 from the first output of the switch 19, which opens the second switch 25 for passing counting pulses, arriving at its first input from the first output of the first counter 9. From the output of the second switch 25, the counting pulses arrive at the counting the third input of the second counter 10. The counting of the number of counting pulses in the counter 10 occurs during the measuring cycle, which is formed by starting pulses and rewriting pulses coming from the outputs corresponding to lei 17 and 18. At the end of the measuring cycle containing 2 measuring cycles from the output of the imager 18 rewrite pulses, a rewrite pulse is sent to the second input of the first register register 11, resulting in digital information contained in the second counter 10 being fed to the first input of the first memory register 11 is rewritten into it.

The decoder 12 converts digital information into the corresponding code received at its first input from the output of the first register 11 of the memory, and supplies it to the first input of the digital indicator 13. In the case of using a liquid crystal display to ensure its normal operation on the Tora input of the indicator 13 and the decoder 12 from the third output of the synchronizer 1 receives rectangular pulses with a duty cycle 2. The formation of the rewriting pulse in the former 18 occurs after

to its third input 2 measurement pulses from the output of the first switch 7, starting from the moment the starting pulse arrives from the second output of the corresponding shaper 17 to the second input of the shaper 18 rewrite pulses, At the first input of the shaper 18 rewrite pulses, clock pulses come from the third output of the synchronizer 1. First electronic key 20 is opened by signal 1 ,. arriving from the first output of the switch 19, the rewrite pulse is passed by the first electronic key 20

to the first input of the second register 21 of the memory, as a result of which the information from the output of the second counter 10 is overwritten into the second register of the memory 21.

The result of the work in the first mode is an indication with the memorization of the input value of the velocity of ultrasound propagation and its memorization in the second register 21 of the memory,

In mode II, switch 19 is set to the second position (1 at the second output, O at the first and third outputs).

The initialization at the beginning of the measuring cycle of the measuring pulse generator 6 is reset to the first and second counters 9 and 10 in the same way as in operation 1.

At the beginning of the measuring cycle, the starting pulses come from the corresponding shaper 17 to the second input of the third counter 22 via the second electronic switch 24 opened for passing this signal by the signal to the second input of the second electronic switch 24 from the second output of the switch 19, thereby overwriting the speed value propagation of ultrasound from the second register 21 of the memory to the second counter 22.

Sync pulse; arriving from synchronizer 1, the generator 2 of the excitation pulses is started, forming a high-voltage pulse c. a steep front front is used to excite an ultrasonic transducer 3s piezoelectric element through a delay line (for example, a forbidden protector) is acoustically connected to an adjustment sample 4 "The received ultrasound converter transducer echo signal, reflected from the opposite surface of an alignment sample 45, is amplified by a selective amplifier 5 and arrives at the first input of the imaging unit 6 measuring pulses, to the second input of which pulses are received from the generator 2 of excitation pulses. The time selection of the echo signals is carried out in a selective amplifier 5; arriving at its second input from the output of the electronic circuit 14 of the delay .. The electronic circuit 14 of the finder is triggered by pulses and the access to its first and second inputs with

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generator 2 of the excitation pulses and the second output of the imaging unit 6 measuring pulses. From the output of the imaging unit 6, the measuring pulses, the duration of which is proportional to the sample thickness, arrive at the first input of the first electronic switch 7. At the input 4 of the first electronic switch 7, the second output of the switch 19 receives a signal 1, which opens the first electronic switch 7 to pass the measuring pulses arriving at his first entry. From the output of the first electronic switch 7, the measuring pulses arrive at the first input of the first circuit And 8, opening it for passing a signal from the output of the generator 16 counting pulses. Thus, at the output of the first circuit 8, each clock forms counting pulses arriving at the first input of the first counter 9, from the second output of which the counting pulses arrive at the second input of the second switch 25. From the second output of the switch 19 to the fourth input of the second switch 25 Signal 1, which opens the second switch 25 to pass the signal to its second input. From the output of the second switch 25, the counting pulses arrive at the counting third input of the second counter 10, the operation of elements 10-13 is completely identical to their operation in mode I. At the same time, the number S, H, + is indicated on the digital indicator 13

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 Sj.aKB g Dy 5c) - thickness of the adjustment sample (mm), numerically equal to the value C, the speed of ultrasound propagation in the material (m / s); S g svc is the increment of the thickness readings (mm) due to time delays in the electron-acoustic path of the ultrasonic thickness gauge, expressed as equivalent Thickness.

Counting pulses from the second output of the first counter 9 also come

to the first input of the third switch 26, which is opened by the signal 1, coming from the second output of the switch 19 to its second input. From the output of the third switch 26 counting

the pulses are passed by the OR circuit 32 to the counting fourth input of the third counter 22. The third counter operates in the subtraction mode, performing the action C to, - (SM) + Sj.rtcn).

Since the adjustment sample is provided with a 8c numerical equality, Crt, at the end of the measuring cycle in the third counter 22 there remains a value Sj expressed in an additional code.

In mode III, switch 19 is in the third position, which corresponds to the presence of level 1 at its third output, and at the first and second outputs - level O.

The installation of the imaging unit 6 of the measuring pulses to the initial state and zeroing of the first counter 9 (Performed in the same way as in the operation in the first and second modes.

The multiplexer 23 is open for the passage of signals from the output of the third counter 22 to the second input of the second counter 10 by signal 1 fed to the fourth input of the multiplexer 123 from the second output of the control circuit 28.

Elements 1-14, 16-18 of the ultrasound thickness gauge work in the same way as in mode II, with the difference that the first switch 7 and the second switch 25 are open for the same signals to pass through the signal 1 coming from the third output of switch 19.

At the beginning of the measuring cycle, the second counter 10 is transmitted through multiplexer 23 to read the value S e "stored in the third counter 22, when the second counter 10 starts a starting pulse from the second output of the corresponding generator 17.

Since the value S, is equivalent to the additional code, when the second counter 10 enters the number of S + counting pulses at the end of the measuring cycle, the second counter 10 accumulates the number of pulses corresponding to the value of thickness S.

The device 27, which includes the elements 29-33, allows you to manually adjust the value of the Z.eq. Stored in the third counter 22, which makes it possible to compensate for the error in the manufacture of the adjustment sample 4.

When the S-j value is corrected. Eq in the direction of decreasing, single pulses come from the second driver 33 single pulses, starting

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by the operator using the button through the OR circuit 32 to the counting input of the third counter 22, k is subtracted from the number stored in it.

When correcting the S i value in the direction of increasing, single pulses come from the first shaper 29: single pulses, triggered by the operator using the button, to the inputs of the shaper 30, delayed pulses, the second circuit 31 and controlling the third input of the third counter 22, reversing the last of the subtraction to the ccp widening mode for the duration of the passage of a single pulse to the fourth counting input of the third counter 22, wherein the value of S.3, (j is increased by one.

Thus, the use of the proposed device improves the accuracy and performance of the control.

Claims (2)

Formula isobteni one . Ultra-sound pulse pulse thickness gauge containing an adjustment sample, serially connected synchronizer, excitation pulse generator, ultrasonic transducer with possibility of mounting on an adjustment sample, amplifier, measuring pulse generator, first switch, first And circuit, and first counter, serially connected second counter, first memory register ti, decoder and digital indicator, electronic delay circuit, input connected to the output of the excitation pulse generator, ora of calibration pulses, inputs connected to the second and third outputs of the synchronizer, and | input - to the second input of the first switch, counting pulse generator, output connected to the second input of the first circuit And, driver of starting pulses, input connected to the third output of the synchronizer and the second inputs of the decoder and a digital indicator, the first output to the third input of the imaging pulse generator, the second output to the second input of the first counter and the first input of the second counter, forming the overwrite pulse, the first input connected to the third output of the synchronizer, the output to the second input of the first memory register, and the third input to the output of the first switch, and the switch, characterized in that, in order to improve the accuracy and performance, connected by the first electronic key, the second memory register, the third counter and the multiplexer, the output connected to the second input of the second counter, the output connected to the second input of the second memory register, the second input The ultiplexer is connected to the common bus; the first input of the first electronic key is connected to the output of the rewrite pulse former, the second input connected to the second output of the starting pulse former, the corrector shaper, the second electronic key, the output connected to the second input of the third counter, the first input - to the second output of the starting pulse former, the second switch, the output connected to the third input of the second counter, the first and second inputs connected respectively to the pen the first and second outputs of the first counter, the third switch, the first input connected to the second output of the first counter, and the output from the input of the correction signal generator, the first and second outputs connected to the third and fourth inputs of the third counter, respectively, the first, second and third transceivers of the switch, respectively, are connected to the third, fourth, and fifth inputs of the first and second switches, the input of the switch is connected to the output of the form. g Yu 15 20 25 Q 35 The world of the overwrite pulses, the second inputs of the first and second electronic switches are connected respectively to the first and second outputs of the switch, the second input of the third switch is connected to the second output of the switch, control circuit, the outputs connected to the third and fourth inputs of the multiplexer, and the input to the third output of the switch, the output of the electronic delay circuit is connected to the second input of the amplifier, and the second input - to the second output of the measuring pulse generator, the second input connected to the output excitation pulse generator, and the thickness of the adjustment sample is selected from condition S and C, where Sda is the velocity of propagation of ultrasonic vibrations in the material of the adjustment sample. 2. Thickness gage according to claim 1, characterized in that the fop of the correction signals is performed from the serially connected first single pulse generator, the delayed pulse former, the second AND circuit and the OR circuit, the second input of which is the input of the correction signal former connected to the third input of the OR circuit of the second single pulse generator, the output of the first single pulse generator is connected to the second input of the second AND circuit; and is the first output of the correction signal conditioner, and the output of the OR circuit is the second output of the correction signal conditioner.