SU589580A1 - Ultrasonic flaw detector - Google Patents

Description

(54) ULTRASOUND DEFECT TESTS

This invention relates to the field of non-destructive testing. A ultrasonic echo pulse flaw detector recording device is known, which contains a logarithmic amplifier, a compensation signal generation unit, a defect signal summation unit, and an indicator I.J. This device has a low measurement accuracy. The closest to the invention to the technical essence is an ultrasonic flaw detector containing successively connected generator of probing pulses, a receiving-transmitting finder, an amplifier, a temporal selector and an analog-to-digital signal processing unit 2. A disadvantage of the known flaws due to the difficulty of isolating and measuring the maximum signal from a defect. The purpose of the invention is to improve the measurement accuracy due to the fact that in the proposed ultrasonic flaw detector an analog-digital signal processing unit is designed as a series-connected comparator, counter, decoder and digital indicator, as well as a code-analogue converter connected between the second comparator input and output counter. The drawing shows the block diagram described flaw detector. The ultrasonic flaw detector contains a probe pulse generator 1 in series, a receiver-transmitter finder 2, an amplifier 3, a time selector 4, and an analog-digital signal processing unit 5 consisting of a series-connected comparator 6, a counter 7, a decoder 8, and a digital indicator 9. Between the second input the comparator 6 and the output of the counter 7 include a code-analog converter 10. The flaw detector works as follows. The pulse of the generator 1, reflected from the defect, is fed to the amplifier 3. The amplified signal is selected by the temporary selector 4 and fed to the first input of the comparator 6. Before the code-analog 10 reflected from the defect pulses from the converter output, the analogue zero level arrives at the second input of the co-parator 6. The first impulse reflected from the defect, received from the temporary selector 4 to the input of the comparator 6, and from its output to the input of the counter 7, sets the latter to

In this case, the analog condition

The output level from the output of converter 10 will be incremented by a discrete value corresponding to code 1.

When the next pulses reflected from the defect arrive at the input of the comparator b, the process repeats until the discretely increasing analog level from the output of the converter 10 n the input of the comparator 6 becomes equal to or greater than the amplitude of the pulse reflected from the defect. Thus, the code of the number stored in the counter 7 turns out to be numerically equal to the maximum amplitude of the pulse reflected from the defect.

The code from the output of the counter 7 enters the decoder 8, the output of which is connected to the input of the digital indicator 9.

The described ultrasonic flaw detector allows you to select and measure the maximum echo signal with great accuracy and memorize its value for any time.

Claims (2)

1. Authors certificate of the USSR 386334, cl. Q 01 N 29/04, 1970. 2. The US patent number 3533280, CL.73-67.9, 1970. G - -