SU785753A1 - Apparatus for quality control of articles by acoustic emission method - Google Patents

Description

This invention relates to non-destructive acoustic emission testing and can be used to control the quality of materials. A device for controlling the quality of products by acoustic emission is known, which contains an amplitude discriminator, a gating pulse generator, a detector and a recorder p. . A disadvantage of this device is the low reliability of the control. The closest to the invention in technical essence and the achieved result is a device for quality control of products by acoustic emission method, which contains an amplitude discriminator, a peak detector and the first generator of gating pulses, connected to the input of the peak detector 2l. Its disadvantage is also low reliability of control. The aim of the invention is to increase the reliability of quality control of products. The goal is achieved by the fact that the device is equipped with an electronic key, the input of which is connected to the output of the amplitude discriminator, two gating pulse generators connected between the electronic key and the first gating pulse shaper and connected to the peak detector output, a counter and an intensity meter, the inputs of which are connected to the output of the second gate of the gating pulses, the output of the third generator of the gate of the pulse and the pulses is connected, with the second input of the electronic key, and the amplitude d skriminator connected pareshlelno peak detector. The drawing shows the block diagram of the proposed device. The device contains an amplitude discriminator 1, a peak detector 2, the first shaper 3 gating pulses, the output of which is connected to the input of the peak detector 2, electronic key 4, the input of which is connected to the output of amplitude discriminator 1, two shaper 5 and G of gating pulses connected between the electronic key and the first driver 3 strobe pulses, the inputs of which are connected to the output of the peak detector 2.

The inputs of the counter 7 and the intensity meter 8 are connected to the output of the gating pulley 5. The output of the imaging unit 6 is connected to the second input of the electronic key 4. Amplitude discriminator 1 is connected in parallel to the peak detector 2,

The device works in the following way.

I Acoustic emission signals taken from the output of the receiving path (not shown in the drawing), are normalized by the amplitude discriminator 1 and, after passing through the electronic key 4, start the shaper 5 of gating pulses. The former is launched from the trailing edge of the pulse generated by the former 5 and, using the electronic key 4, prohibits the supply of normalized pulses to 3yans. shaper 5 at the time of its recovery. The duration of the gate selection pulse, equal to the total exposure time of the formers 5 and b, is chosen equal to the time t after the transducer and the controlled product at the discrimination level

The duration of the pulses produced by the formers 5 and C is proportional to the voltage removed from the peak detector 2 s. regulate number 1m transfer coefficient. Peak detector 2 outputs, for example, a system proportional to the logarithm of the ratio of the maximum amplitude of the recorded acoustic emission pulse U (3 to the discrimination voltage 11c.) At the end of the selection strobe, the peak detector 2 is reset by a short pulse produced by the driver 3 of the gating pulses. Shaper 3 is launched from the trailing edge of the cell produced by the shaper b.

The amplitude-normalized pulses from the output of the former 5 are fed to the inputs of the intensity meter 8 and the counter 7, where the intensity and the total number of gating selection pulses are calculated.

Thus, the device offered by foe allows to increase the reliability of the control.

Claims (2)

1. Author's certificate of the USSR 534687, cl. G 01 N 29/04, 1975. 2. Authors certificate of the USSR. 419789, cl. G 01 N 29/04, 1972 (prototype).