SU1002954A1 - Ultrasonic flaw detector - Google Patents

Description

(54) ULTRASOUND DEFECT TESTS

one .

The invention relates to non-destructive ultrasonic testing and can be used to control coarse-grained materials.

A device for ultrasonic testing of products from coarse-grained materials is known, comprising a pulse generator, a receiving-amplifying unit, a synchronizer, a switch and a finder made in the form of a package of piezoplates of various frequencies, and that electron tube 13.

A disadvantage of the known device is the low accuracy and reliability of the control due to the unequal temporal position on the screen of the indicator of echo pulses from the same defect for different frequencies.

The closest to the invention in technical essence and the achieved result is an ultrasonic flaw detector containing serially connected synchronizer, probe pulse generator, shaper of n spectrum frequencies and a converter, n amplifiers, the first input of each of which is connected to the converter, an indicator and a sweep generator connected between synchronizer and G2T indicator.

A disadvantage of the known device is the low reliability of the control, since the time selection

10 signals with frequencies f, ..., fj, are produced after they are amplified in separate amplifiers, with the passage of which they undergo frequency and phase distortions.

15

The purpose of the invention is to increase the reliability and accuracy of the control.

Claims (2)

The goal is achieved by the fact that the ultrasonic flaw detector is equipped with a series-connected mixer, the inputs of which are connected to the output of each amplifier, a frequency selector and an amplifier of the 3-dimensional frequency, the output of which is connected to the input of the indicator. The drawing shows a block diagram of a flaw detector. The ultrasonic flaw detector contains a series-connected syncronizer 1, a generator of 2 probe pulses, a driver 3, and a frequency spectrum and a transducer k. The h connected in parallel with each other are connected to the converter. amplifiers 5; A block 6 of the temporary gain control is turned on between synchronizer 1 and each amplifier 5 pulses. In addition, the ultrasonic defekoscope contains sequentially connected mixer 7, whose inputs are connected to the outputs of amplifiers 5, frequency selector 8, amplifier 9 of total frequency and indicator 10. Sweep generator 11 is turned on between synchronizer 1 and indicator 10. Ultrasonic flaw detector works as follows. Synchronizer 1 starts a generator of 2 probe pulses, generating a high-frequency pulse arriving at shaper 3 of the spectrum mast, which generates an electrical pulse, the frequency spectrum of which includes frequencies t), ... fy ,. The transducer k converts this electrical impulse into pulses of ultrasonic vibrations, which are reflected from defects and structural inhomogeneities during the passage of the monitored product and are again converted into an electrical impulse by the transducer. Then, this pulse arrives at amplifiers 5, where the component frequencies of the f, ..., fvi spectrum are selected. Voltage from blocks 6 of the time gain control is supplied to the second inputs of the amplifiers 5. From the outputs of amplifiers 5, the components of the spectrum of the signal frequency f, ... fj /, from defects or structural inhomogeneities enter the frequency mixer 7 where the oscillations of these frequencies occur, and a signal is generated at its output, the spectrum of which includes an oscillation with a total frequency fj-, which is present only with signals from defects obtained simultaneously from all amplifiers 5C of the output of the mixer 7, signals are sent to the frequency selector 8, which isolates signals from defects with a total frequency f, which arrive to the amplifier 9 sums molecular frequencies where amplified, detected and supplied to an indicator 10 representing a cathode ray tube. A sawtooth voltage is supplied to the horizontal deflection plates of the indicator 10 from the sweep generator 11. The invention allows, with high accuracy and reliability, control of coarse-grained materials due to the frequency selection of signals from defects against the background of structural inhomogeneities. Ultrasonic flaw detector containing a synchronously connected synchronizer, a probe pulse generator, a shaper of frequency spectrum and a converter, n amplifiers, the first input of each of which is connected to the converter, an indicator and a sweep generator connected between the synchronizer and the indicator. the purpose of increasing the accuracy and reliability of the control, it is equipped with a series-connected mixer, the inputs of which are connected to the output of each amplifier, frequency selector and amplifier total frequency, the output of which is connected to the input of the indicator. Sources of information taken into account during the examination 1. USSR author's certificate No. 19785, cl. G 01 N 29 / Oi, 19b9. 2. USSR author's certificate W 568012, cl. G 01 N 29/0, 1975 (prototype).