SU1425467A1 - Device for measuring ultrasound velocity in materials - Google Patents

Abstract

The invention relates to a measurement technique and can be used to measure the speed of ultrasound in materials, in particular in concrete. The purpose of the invention is to improve the measurement accuracy. The device contains a synchronizer 1, a generator of 2 pulses, radiating and receiving acoustic transducers 3 and 4, N-channel amplifier 5, key 6, peak detector 7, voltage divider 8, first 9, second 10, third 16 and fourth 17 voltage comparators , the first 11, the second 12 and the third 14 triggers, the time interval meter 13, the extremator 15, the equivalence circuit 18, the coincidence circuit 19 and the reversible counter 20. In sample 21 of the material under study, ultrasonic oscillations are excited by an acoustic transducer 3 With a transducer 4, they are amplified by an amplifier 5 and through a switch 6 they go to an extremator 15, at the output of which they receive pulses that coincide with the extremes of the pulses of the first injection. The amplitude of the first arrival pulse is analyzed by voltage comparators 16 and 17, to which the reference voltages are applied, Ui and U2, respectively, according to the results of analysis using the equivalence circuit 18, the coincidence circuit 19 and the reversible counter, the required gain channel is selected. 1 il. i (L

Description

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The invention relates to a measurement technique and can be used to measure the speed of ultrasound in materials, in particular in concrete.

The purpose of the invention is to improve the measurement accuracy.

The drawing shows a block diagram of the device.

The device contains a series-connected synchronizer 1, generator 2

acoustic transducer 4. The signal from the output of the latter is amplified by a N-stage amplifier 5 and through the switch 6 is fed to the input of the extremator 15. At the output from the extremer 15, pulses coincide with the extremes of the first entry pulses. These pulses reset the third trigger 14, which closes the key 6. At the output of the key b, a periodic sequence of pulses and an emitting acoustic transducer with a duration from the moment of the first distributor 3 are received, connected in series to the first extremum, which

receiving acoustic transducer 4, N-stage amplifier 5, key 6, more recently goes to peak detector 7.

and inputs of comparators 9 and 10 voltages. From the peak detector 7, voltage, flat, first 9 and second 10 comparators. the amplitude of the first input voltage, the first inputs of which are connected to the divider 8, the voltage detector 7 and the divider 8 are connected to the output of the key 6, and the second inputs to the corresponding outputs of the voltage divider 8, the first trigger 11 whose first input is connected to the synchronizer 1, and the second input to the output of the first voltage comparator 9, the second trigger 12, the first and second inputs of which are connected respectively to the outputs of the first 9 and second 10 voltage comparators, the meter 13 time intervals, cat inputs connected to the outputs of the first 11 and second 12 flip-flops, the third trigger 14, the first input of which is connected to the synchronizer 1, and the output - to the control input of the key 6, extremator 15, the input of which is connected to the output of the key 6, and the output to the second the input of the third trigger 14, the third 16 and the fourth 17 voltage comparators, the first inputs of which are connected to the output of the key 6, and the second inputs are intended to supply the reference voltages Ui and U2, respectively, the equivalence circuit 18, the inputs of which are connected respectively to the outputs of the third 16 and fourth 17th voltage comparators, 19 coincidence circuit, first

nor, from the outputs of which the reference voltages Uoi KiAi and Uo2 К2А | come to the second inputs of comparators 9 and 10. The first comparator 9, triggered 20 by the level of Uoi, resets the first trigger 11 to form an output pulse with a duration of T-j-Ati, where T is the time from the synchronizer pulse to the moment of the first entry; Ati - the time from the moment of the first entry to the moment of cp25

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battling the first comparator 9 voltage. This impulse arrives at the summing input of the measuring unit of 13 time intervals.

Simultaneously with the reset of the second trigger 12, which is reset by the second comparator 10, triggered by the level Uo2, a pulse of duration At2 is generated at the output of the second trigger 12 from the moment the first comparator triggers until the second voltage comparator 10 trips. This pulse is fed to the subtractive input of the meter 13 time intervals, the output of which receives, for example, in the digital code the value of T + Ati-At2. The values of Ki and K2 of the second input of which are podtuyucheny corresponding to 40 such that the ratio is fulfilled, resulting in a value of T, corresponding to the time of ultrasound propagation.

From the output of the key 6, the signal is fed to the reverse control connected to the output to the first inputs of the third 16 and fourth to fourth voltage comparator 17, which is 17 voltage comparator. Third

the comparator 16 is triggered by the level Ui, and the fourth comparator 17 is triggered by the level U2. The pulses from the outputs of the third 16 and fourth 17 comparators are directly connected to the outputs of the extremator 15 and the equivalence circuit 18, a reversible counter 20, the counting input of which is connected to the output of the coincidence circuit 19, the input

the output is to the control input of the N-stage amplifier 5. In addition, the drawing shows sample 21 of the material under study.

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The device works as follows: Q does not go to the first and second inputs.

equivalence circuits 18, at the output of which a signal appears when the third 16 fourth 17 voltage comparators are in the same state. The output signal from circuit 18 of the equivalent of synchronizer 1 is a periodic sequence of pulses to start a generator of 2 pulses, the first trigger 11 and the third trigger 14. In the equivalent circuit diagram 18, the output of which appears is the signal when the third 16 fourth 17 voltage comparators are in the same condition. The signal from the output of circuit 18, equivalent to 21 of the material under study, with a capacity of 55, goes to the first input of circuit 19

By the power of the radiating acoustic transducer 3, ultrasonic vibrations are excited which are adopted by the receiving

match, the second input of which receives pulses from the output of the extremator 15.

acoustic transducer 4. The signal from the output of the latter is amplified by the N-stage amplifier 5 and through the switch 6 is fed to the input of the extremator 15. At the output of the extremator 15, pulses coincide with the extremes of the first entry pulses. These pulses reset the third trigger 14, which closes key 6. At the output of key b, a periodic sequence of pulses of duration from the moment of the first entry to the first extremum is obtained, which

nor, from the outputs of which the reference voltages Uoi KiAi and Uo2 К2А | come to the second inputs of comparators 9 and 10. The first comparator 9, triggered by 0 at the level of Uoi, resets the first trigger 11 to form an output pulse with a duration of T-j-Ati, where T is the time from the synchronizer pulse to the moment of the first entry; Ati - time from the moment of the first entry to the moment of

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battling the first comparator 9 voltage. This impulse arrives at the summing input of the measuring unit of 13 time intervals.

Simultaneously with the reset of the second trigger 12, which is reset by the second comparator 10, triggered by the level Uo2, a pulse of duration At2 is generated at the output of the second trigger 12 from the moment the first comparator triggers until the second voltage comparator 10 trips. This pulse is fed to the subtractive input of the meter 13 time intervals, the output of which receives, for example, in the digital code the value of T + Ati-At2. Ki and K2 values are taken to the first and second inputs.

equivalence circuits 18, at the output of which a signal appears when the third 16 fourth 17 voltage comparators are in the same state. The signal from the output of the equivalent circuit 18, to the second input of which impulses come from the output of the extremator 15.

pulse generator and radiating acoustic transducer, serially connected acoustic transducer, N-stage amplifier, key, peak detector and voltage divider, first, second and third voltage comparators, the first inputs of which are connected to the outputs of the key, the second inputs of the first and second comparators the voltages are connected to the corresponding outputs. From the output of the circuit 19 coincidence, the counting input of the reversible counter 20 receives counting pulses corresponding to the extrema of the impulses. lsov first entry in the moments when the amplitude of pulses with a first entry. If, then at the output of the counter 20, after counting the pulses from the output of the coincidence circuit 19, a code is established with which the input ,. , „„

the key 6 is connected to the output of the N-step voltage, the second input of the third one of the amplifier 5 with a higher voltage ratio is intended for

the gain amplitude, at which .- supplying the reference voltage U to it :, If, then at the moment of counting the first trigger, the first input of which

the control input of the reverse of the counter 20 is connected to the synchronizer, and the second input is connected to

A signal is output from the output of the fourth 5 with the output of the first comparator of the voltage comparator 17, the production count, the second trigger, the first and the second, enter in the opposite direction, as a result of which they are connected respectively to

those to the input of the key 6 is connected to the outputs of the first and second comparators

N-stage amplifier with a lower voltage ratio, interval meter gain amplification at which, the inputs of which are connected to the corresponding Ai: U2. The minimum value of the coefficient 20 to the outputs of the first and second amplification triggers of the first stage amplifier 5gerov, the third trigger, the first input which the maximum value of the gain after the last stage of amplifier 5 is determined from the ratios:

K. “MK. - l / Alnwn; .

where, AikNI A | rt «t - is the minimum and maximum magnitude of the amplitude of the first entry.

The gain of each of the stages, starting with the second, is determined by the corresponding voltage of the voltage, the first input of which is worn Kve.cm..U2 / U .. The number of steps is connected to the output of the key, and the second input

it is intended to supply to it a reference voltage Uo, an equivalence circuit, the inputs of which are connected respectively to the outputs of the third and fourth voltage comparators, and the output to the second input of the coincidence circuit, and a reversible counter, the counting input of which is connected to the output of the coincidence circuit the reverse control input is with the output of the fourth voltage comparator, and the output is

is connected to the synchronizer, and the output is connected to the control input of the key, an extremator whose input is connected to the output of the key, and an output to the second input of the third trigger, and a coincidence circuit, the first input of which is connected to the output of the extremator, that, in order to improve the measurement accuracy, it is equipped with the fourth amplification amplifier 5, determined from the ratio

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Claims (1)

Invention Formula Device for measuring speed - g. .,. ultrasound in materials containing along with the control input of the N-channel usi- consequently connected to the synchronizer, littel. pulse generator and radiating acoustic transducer, serially connected acoustic transducer, N-stage amplifier, key, peak detector and voltage divider, first, second and third voltage comparators, the first inputs of which are connected to the outputs of the key, the second inputs of the first and second comparators the voltages are connected to the corresponding outputs, de,. , „„ voltage module, the second input of the third voltage comparator is intended for voltage torus, the first input of which is connected to the output of the key, and the second input It is connected to a synchronizer, and the output is connected to the control input of the key, an extremator whose input is connected to the output of the key, and an output to the second input of the third trigger, and a coincidence circuit, the first input of which is connected to the output of the extremer, characterized in that In order to improve the accuracy of measurements, it is equipped with a fourth