SU480975A1 - Device for measuring the speed of ultrasound - Google Patents

Description

pym selector 7, which, in addition, through the amplifier 4 is connected to the receiving transducer 3.

The time selector is connected to a matching AND circuit with two parallel circuits, one of which passes in series through shaper 10, delay line 9 and strobe pulse generator 8, and the second through differential circuit 12. The coincidence circuit is connected to a probe pulse generator.

The device works as follows.

Under the action of probing pulses (diagram 13), the emitter 2 creates ultrasonic oscillations in the test medium, which the transducer 3 converts into electrical oscillations (diagram 16). These oscillations, through amplifier 4, arrive at the input of the time selector 7. At the second input of the selector, from generator 6, which is started via delay line 5 by the same probe pulses, wide strobe pulses pass (Figure 15).

The temporal selector includes a square-shaped pulse former (figure 17), which are formed from the half-wave received oscillations (

16) if these oscillations coincide with a wide strobe pulse (Diagram 15). From the first right-angled impulse of this series, the shaper 10 forms the unipolar phE 1Y pointed pulse (diagram 18) arriving at the delay line 9. The delay line creates a pulse (diagram 20) whose falling edge triggers the generator 8, producing narrow strobe pulses (diagram 21), Matches arriving at the circuit. The second input of this circuit receives a series of rectangular pulses (diagram

17) selectors, which after the differential chain have the shape shown by the diaphragm 19. When a narrow pulse coincides with one of the differentiated impulses, a short pulse occurs at the output of the coincidence circuit (diagram 22), which triggers the probe pulse generator.

Thus, along the circuit closed through the acoustic channel, an auto-circular impulse occurs.

The use of a selector allows one to start a generator of narrow strobe pulses of the first half-wave oscillations received at the output of the medium under study, and the use of a differential chain increases the area of possible

capture start their pulses. These measures allow with sufficient accuracy to use for the study of lower frequencies than in known devices.

Subject invention

An apparatus for measuring the speed of ultrasound, based on the method of pulse autocirculation through the test medium and containing a probe pulse generator connected to an emitter and a time selector that includes a delay line, a strobe pulse generator, an Sphinc circuit, a receiving transducer connected through an amplifier to a time selector connected to a coincidence circuit connected to a probe pulse generator, characterized in that, in order to improve the accuracy and broaden the selection zone, first gating pulse, therein temporary selector output is connected to the coincidence circuit via shaper pointed unipolar pulse, a delay line oscillator pulses, and the narrow differential chain.

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