SU486270A1 - Automatic defect detector for ultrasonic flaw detectors - Google Patents

Description

one

The invention relates to the field of testing products using an ultrasonic method and can be used to control pipes, sheets and other products of metallurgical production.

Automatic defect signaling devices for ultrasonic flaw detectors are known, comprising a device connected in series to form a control zone, a selector and an analog output device.

However, in such a device, the effective value of the extracted signal in analog form depends on the frequency of the defect and the location of the defect in depth: during the non-period of time from the synchronization pulse before the arrival of the signal reflected from the defect, there is no analog signal. This leads to a significant loss of information in case of bottom defects.

The aim of the invention is to improve the accuracy of the control.

This is achieved due to the fact that the device is equipped with two series-connected peak detectors with an interconnect located between the selector output and the analog output device.

FIG. 1 is a block diagram of the device; Fig. 2 is a voltage chart illustrating the operation of the device.

The automatic defect detector for ultrasonic flaw detectors contains a control zone, a selector 2, and two peak detectors 3 and 4, connected in series to shaper 1, and the second input of selector 2 is connected to a video amplifier. The input of the imaging unit 1 zone. Control and the reset input of the first peak detector 3 is connected to the source of synchronization pulses, and the reset input of the second peak detector 4 is connected to the imaging unit 1 of the control zone. A recording device can be connected to the output of the second peak detector 4.

The voltage diagram has the following notation:

a - synchronization pulse;

b - gating impulse of the control zone;

in - differentiated rear edge of the gating pulse of the control zone;

g - video signal reflected from the product;

d - the pulse selected by the selector 2;

e is the output of the first peak detector 3;

W - output of the second peak detector 4 (analog output).

The device works as follows.

A synchronization pulse is applied to the input of the imaging unit 1 of the control zone. From the output of the imaging unit 1 of the control zone, the strobe pulse b is fed to the selector 2. To the other input of the selector 2, the video signal g of the pulse reflected from the defect is supplied. The pulse g selected by the selector 2 goes to the first peak detector 3. The first peak detector 3 is reset. It is carried out by the synchronization pulse a. Voltage e from the first peak detector 3 is fed to the input of the second peak detector 4. The second peak detector 4 is reset by the falling edge of the strobe pulse of the control zone from the coitrol zone former 1. The first peak detector 3 performs intermediate storage of the amplitude of the selected video signal over a period of time from the video signal to the sync pulse. The second peak detector 4 memorizes the voltage at the output of the first peak detector 3 during the whole time of the follow-up period except for the short and constant in duration of the reset pulse (the length of the back edge of the reset). Consequently, the magnitude of the signal at the output of the second peak detector 4 does not depend on the frequency and the location of the defect.

Subject invention

An automatic defect detector for ultrasonic flaw detectors containing a series-connected device for forming a control zone, a selector and an analog output device, characterized in that, in order to improve accuracy, it is equipped with two series-connected peak detectors with a reset located between the selector output and the analog output device .