SU1552094A1 - Apparatus for ultrasonic inspection of quality of materials and articles - Google Patents

Abstract

The invention relates to the technique of ultrasonic quality control of materials and products and can be used in the construction, engineering and other industries in non-destructive testing systems. The purpose of the invention is to increase the reliability of control by reducing the phase distortions in the received signals. Using a two-period rectifier, the first half period of the received signal is inverted in cases where the sign of the first entry in the received signal is distorted, which increases the reliability of quality control of materials. 2 Il.

Description

The invention relates to the technique of ultrasonic quality control of materials and products and can be used in the construction, engineering and other industries in non-destructive testing systems.

The purpose of the invention is to increase the reliability of control by reducing the phase distortions in the received signals.

FIG. 1 shows a block diagram of a device for automating ultrasonic quality control of materials and products; in fig. 2 - time plots of signals, explaining his work.

A device for ultrasonic quality control of materials and products contains a series-connected synchronizer 1, a generator of 2 probe pulses and a radiating electro-acoustic transducer 3, a serially connected receiving electro-acoustic transducer 4 and an amplifier 5, a differentiating amplifier 6, a threshold element 7 and a meter 8 time intervals connected to the output of the amplifier 5 full-wave rectifier 9, the output of which is connected to the input of the differentiating amplifier 6, and connected to course of the last series-connected the detector 1 CO

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the torus 10, the second differentiating amplifier 11, the amplifier-limiter 12 and the analog switch 13, the output of which is connected to the input of the threshold element 7 connected to the output of the last coincidence circuit 14, the output of which is connected to the input of the meter 8 time intervals connected to the output of the synchronizer 1 in series connected to the delay line 15 and the strobe pulse shaper 16, the output of which is connected to the control input of the analog switch 13 and to the second input of the coincidence circuit 14, the output of the synchronizer 1 is connected to the second input of the measurement erator 8 slots.

The device works as follows.

The synchronizer 1 generates a sync pulse 18 (Fig. 2), a trigger generator 2 probe pulses O The electric pulse generated by the generator 2 excites in the converter 3 an ultrasonic pulse emitted into the controlled material 17. The transmitted ultrasonic pulse (converted by the converter 4 into (electric signal 1 9 which is amplified together with the regular noise amplifier 5.

With one-sided sounding of a bushy inhomogeneous material, the consequence of the interference of longitudinal and transverse waves on small sound bases and the instability of the point contact of the conical waveguides of the transducers 3 and 4 with the surface of the material 17 can cause the first input phase of the received signal to change. differentiation in a certain polarity (in Fig. 2 shows the signal conversion for half-waves of positive polarity) to the dual output of amplifier 5 is connected two-pole -period rectifier 9. In the case on arrival signal rectifier 9

20 in opposite phase, its first negative half-wave is inverted and the further formation of a short signal front in the zone of the first extremum is accomplished by converting only the positive half-wave

21 or 2 2.

From the output of rectifier 9, signal 23 is fed to differentiating amplifier 6. Differentiated signal

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five

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24 is detected by the detector 10 and its now negative half-wave 25 is re-differentiated by the second differentiating amplifier 11. The final formation of the short leading edge of the twice-differentiated signal 26 is carried out in the limiting amplifier 12.

The pulse 27 formed by the limiting amplifier 12 passes unchanged through the analog switch 13 and enters the threshold element 7, the threshold of which in the absence of regular interference is set at a level close to zero, and with slight interference - with some exceeding their level. A rectangular impulse 29, emulated by the threshold element 7, arrives at the first input of the coincidence circuit 14.

To control the analog key 13 and the coincidence circuit 14, the synchronizer 1 starts a delay line 15, the output of which receives a pulse

30 with adjustable duration. The last edge of the latter is launched by the strobe pulse shaper 16, which forms an adjustable temporary strobe.

31 control at the same time applied to the control input of the analog switch 13 and the second input of the junction circuit 14. By delay 30, a temporary gate 31 is set in the time domain corresponding to the expected arrival of the first half-wave of the signal in the absence of regular interference,

and for tolerance testing, in the area of the normalized strength value of the material being monitored.

The simultaneous arrival on the circuit 14 of the pulses 29 and 31 leads to the formation of a rectangular pulse at its output with parameters similar to the pulse 29. The meter 8 time intervals, controlled by the synchronization pulse 18 and the pulse 14 formed by the circuit 14, measures the passage of the ultrasound pulse in the controlled material 17,

Compensation of the signal delay time in the elements of the electroacoustic path of the device can be carried out by the delay line Sne (shown), switched on between synchronizer 1 and the meter 8 time intervals.

The invention makes it possible to increase the reliability of control in case of one-sided and through-sounding of the controlled material by reducing the phase distortions in the received signals.

Claims (1)

Invention Formula A device for ultrasonic quality control of materials and products, containing a series-connected synchronizer, probe pulse generator and radiating electro-acoustic transducer, a series-connected receiving electro-acoustic transducer and amplifier, a differentiating amplifier, a threshold element and a time interval meter, with a two-half-wave rectifier , the output of which is connected to the input of the differentiating amplifier, connected to the output of the last sequence connected by a detector, a second differentiating amplifier, a limiting amplifier and an analog switch, the output of which is connected to the input of the threshold element connected to the output of the latter by a coincidence circuit whose output is connected to the input of the time interval meter connected to the output of the synchronizer 5 serially connected by a delay line and a strobe pulse shaper, the output of which is connected to the control input of the analog switch and to the second input of the coincidence circuit, It is so that, in order to increase the synchronizer output, it is connected to the second reliability of the control, it is connected to the output of the amplifier to the input of the interval meter. Phie.1