SU402734A1 - DEVICE FOR MEASURING THE SPEED OF ULTRASOUND VIBRATIONS IN SAMPLES - Google Patents

Description

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The invention relates to the field of acoustics and ultrasound technology and can be used in the design of instruments for measuring the velocity of propagation of ultrasonic vibrations in materials and samples at high thermodynamic parameters.

Devices are known for measuring the speed of ultrasonic oscillations in samples, comprising a synchronizer, an excitation geyetor, an adjustable zaderlsky line, a piezo emitter, a piezo receiver, an amplifier, a measuring trigger, a time-to-amplitude converter, an indicator, and a recorder.

However, the known devices have a large measurement error due to the amplitude spread of the first half-period of the ultrasonic pulse, which significantly reduces the resolution of the device.

The proposed device differs from the known ones in that it is equipped with a selector of the first half-period of the ultrasonic pulse, the input of which is connected to the output of the amplifier, and an amplitude discriminator, one of the inputs of which is connected to the output of the selector, and the other through the memory circuit, while the output of the discriminator is connected to input measuring trigger.

Such an embodiment of the device makes it possible to reduce the influence of the amplitude spread of the first half-period of the ultrasonic pulse on the accuracy of measuring the propagation speed of ultrasonic oscillations in materials and samples with different ultrasound attenuation coefficients under conditions of varying high pressures and temperatures.

FIG. 1 is a block diagram of the described device; in fig. 2 - diagrams for example.

The device contains a synchronizer 1, connected to the input of the excitation generator 2 and to the input of the adjustable delay line 3. The excitation generator 2 is connected to the piezo-emitter 4. The output of the line 3 Zaderlsky is connected to the input of the measuring trigger

5. Between the piezoelectric transducer 4 n the piezo receiver 6 is sample 7. The piezo receiver 6 is connected to the input of the amplifier 8, the output of which is connected to the input of the selector 9. The output of the selector 9 is connected to the input of the amplitude discriminator 10 and to the input of the amplitude memory 11 of the first half-period of the signal. The output of the discriminator 10 is connected to the input of the trigger 5, the output of which is connected to the input of the converter 12 time intervals in amplitude, and the output of the converter 12 to the input of the indicator 13. The output of the indicator 13 is connected to the recorder 14.

The device works as follows.

Synchronizer 1 generates sync pulses (plot a) fed to generator 2. Generator 2 generates electrical pulses that trigger the piezo emitter 4. Simultaneously, synchronizer 1 sends a pulse through an adjustable line of the delay 3 (plot b) to tip over trigger 5 (plot c). The piezo emitter 4 communicates the elastic oscillations to the test sample 7. The elastic pulse transmitted through the sample 7 is converted into an electrical signal by the piezopathic 6 and amplified by the amplifier 8 (enurer). The selector 9 selects from the received signal the first oscillation half-life (plot d). This sigpal is remembered by circuit 11. The constant voltage corresponding to the amplitude of the first impulse impulse adjusts the sensitivity of the discriminator 10 in such a way that it is increased for signals of small amplitude, i.e.

The threshold is triggered by the discriminator 10 varies in proportion to the first zero period of the ultrasonic pulse.

Subject invention

A device for measuring the speed of ultrasonic oscillations in samples, containing a synchronizer, an excitation generator, an adjustable delay line, a radiator, a resonator, an amplifier, a measuring trigger, a converter of time intervals to an amplitude, an indicator and a recorder, characterized in that

precision, it is equipped with a selector of the first half-period of the ultrasonic pulse, the input of which is connected to the output of the amplifier, and an amplitude discriminator, one of the inputs of which is connected to the output of the selector

directly, and the other through the memory circuit, where the discriminator output is connected to the input of the measuring trigger.

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