SU1223137A1 - Method and arrangement for material ultrasonic inspection - Google Patents

Abstract

The invention relates to non-destructive testing and can be used to determine the permeability of a fluid through fibrous, porous and film materials using ultrasonic vibrations. The aim of the invention is to determine the permeability of a liquid through the material under study. In the device for ultrasonic testing, the oscillation amplitude and its derivative with time are varied with the help of a differentiator and a control unit, the magnitude of which changes as the material under study is filled with liquid. A reservoir for the working fluid, a pipeline equipped with an electromagnetic valve, and a recess made on the surface of the radiator, allow the liquid to be supplied to the surface of the controlled product at a predetermined pressure. The method and device for ultrasonic testing allows reliable determination of fluid permeability through materials by stabilizing the amplitude level of acoustic signals transmitted through the sample. 2 sec. f-ly, I ill. IsS Yu 00 co

Description

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The invention relates to non-destructive testing and can be used to determine the permeability of a liquid through fibrous, porous and film materials using ultrasonic ultrasound.

The aim of the invention is to determine the permeability of a liquid through the material under study.

The drawing shows the proposed device for ultrasonic testing of materials.

The device comprises a housing 1 with an internal damping gasket 2, an electric oscillation generator 3, an ultrasonic emitter 4, an ultrasonic receiver 5, a starting block 6, an electric signal level meter 7, a differentiator 8, a control block 9, a time counter 10, a reservoir 11 for operating fluid with a pipe 12, equipped with an electromagnetic valve 13, the output of the ultrasonic receiver 5 is connected to the input of the meter 7 electric signal, the output of which is connected to the input of the differentiator 8, the output of which is connected to W One input of the control unit 9, the first input of which is connected to the input of the meter 7 of the electric signal level. The output of the control unit 9 is connected to the second input of the electronic stopwatch, the first input of which is connected to one of the outputs of the starting unit 6. The other two outputs of the starting block 6 are connected respectively to the coil of the electromagnetic valve 13 and to the synchronization input of the generator of electrical oscillations. Case 1 consists of upper and lower parts. An ultrasonic emitter 4 is installed in one of them, an ultrasonic receiver 5 is placed in the other one. Test sample 14 is placed between them and, pressing both parts of case 1, clamp the sample by bringing one of its surfaces into contact with the emitter 4 and the other in contact with the receiver 5. The clip is made using the latch lock of the housing 1. On the surface of the radiator 4 facing the surface of the test sample 14, a flat notch 15 is made, which when the radiator 4 contacts the sample 14 forms a cavity 16 for applying the working fluid on the surface of the sample 14.

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The method of ultrasonic testing of materials is carried out as follows.

The test sample 14 is fixed in the housing 1, the start-up unit 6 is turned on, which simultaneously turns on the generator 3 of electrical oscillations, opens the solenoid valve 13 and starts the time counter 10. The working fluid from the reservoir 11 through the open electromagnetic valve 13 under a predetermined constant pressure and temperature enters the cavity 16. The electric oscillations excited by the electric oscillator 3 arrive at the input of the radiator 4, where they are converted into acoustic oscillations that are directed through the filled liquid cavity 16 and sample 14 to the input of the receiver 5. The electric signal level meter 7 connected in series with the receiver 5 records the change in the electric level with ignal and outputs it to the input of the differentiator 8 and to the first input of the control unit 9. Differentiator 8 extracts the first derivative of the change in the level of the electrical signal and sprinkles the signal on the second input of control unit 9.

The control unit 9, in the presence of a signal at its first input, controls the magnitude of the signal arriving at its second input from the output of the differentiator 8. When a second signal appears at its second input (corresponds to the zero value of the first derivative with respect to the change in the level of the electrical signal), control unit 9 signal to the second input of the counter 10 time.

At the first input of the control unit 9, the signal is present only at the moment of operation of the meter 7 level of the electrical signal. Time counter 10 that is turned on simultaneously with the source of acoustic oscillations counts time. The next moment, the process of liquid penetration into sample 14 begins. This leads to an increase in the amplitude of acoustic waves passing through the material, and accordingly to an increase in the level of electrical signals detected by the meter 7, and to an increase in the first derivative of the amplitude in time allocated by the differential 8. In the point in time when the liquid passes the sample 14, the amplitude level of the acoustic signal is stabilized. Differentiator 8 allocates a zero value to the first derivative. The control unit 9 fixes the zero value of the signal at its second input and at this moment issues a signal to the second input of the time counter 10, which is turned off. Consequently, the time counted by the counter 10 corresponds to the instant of the appearance of the liquid on the opposite surface of the sample.

Claims (2)

1. The method of ultrasonic testing of materials, consisting in that ultrasound vibrations are excited in the controlled material, taken in and measured by the amplitude of the received signals, characterized in that, in order to determine the permeability of the liquid through the material under study, liquid is applied to the material surface they register the change in the amplitude of ultrasonic oscillations with time, fix the moment of stabilization of the amplitude and 223137 it is used to determine the permeability of the fluid through the material. 2. A device for ultrasonic testing of materials, containing an ultras5 ultrasonic emitter, an electrical oscillator, a trigger unit connected in series to the radiator, an ultrasonic oscillation receiver, an electric signal level meter and a time counter connected in series to the receiver, the second time counter input is connected to the second the output of the startup block, characterized by 15 that, in order to determine the permeability of the fluid through the material under study, it is additionally equipped with a differentiator, a control unit, successively installed between an electric signal level meter and a time counter, the output of the level meter is connected to the second control unit inlet, fluid reservoir, and pipe connected 25 with a reservoir, an electromagnetic valve installed at the exit of the pipeline and connected to the third outlet of the start-up unit, with a high-level connection (with the pipeline) connected to the working surface of the radiator.