SU1137384A1 - Device for measuring speed of ultrasound - Google Patents

Abstract

MEASURING DEVICE FOR ULTRASONIC SPEED, containing connected PS4, sequentially probing pulse generator, emitting and receiving transducers with protective membranes, selector, amplifier, first and second triggers, switch, connected, second input with output of the first trigger, integrator, controlled generator, switch, integrator, controlled generator, connected, second input with output of the first trigger, integrator, controlled generator, switch, integrator, controlled generator, connected, second input with output of the first trigger, integrator, controlled generator, divanter, controlled switch, coupled. frequency and pulse distributor connected by the first output to the input of the probe pulse generator, the second output to the second input of the second trigger and the third output to the second input of the first about the trigger, and a recorder connected to the output of the controlled generator, about and in part because, in order to improve measurement accuracy, it is equipped with a delay line connected between the output of the probe pulse generator and the second | input selector.

Description

1

eleven

The invention relates to acoustic measurements. It can be used mainly in hydrophysical studies.

A device is known for measuring the speed of sound, which contains a generator of probe pulses connected in series, emitting and receiving transducers with protective membranes, an amplifier, an adjustable delay, and a pulse selector.

A disadvantage of the known device is the low accuracy of measurements caused by parasitic acoustic delays in protective membranes.

The closest to the proposed technical essence and the achieved result is a device for measuring the speed of ultrasound, containing a series-connected probe pulse generator, emitting and receiving transducers with protective membranes, a selector, an amplifier, first and second triggers, a switch connected by a second input to the output of the first. trigger trigger, integrator, controlled oscillator, frequency divider and pulse distributor connected by a first output to the generator input probing pulse in, the second output - to a second input of the second flip-flop and a third output to a second input of the first flip-flop and soedinenny ,, yield controlled oscillator recorder 2}.

A disadvantage of the known device is the low measurement accuracy due to the error introduced by the delay in the zagstatnyh membranes.

The purpose of the invention is to improve the measurement accuracy.

The goal is achieved by the fact that a device for measuring the speed of ultrasound, containing a series-connected probe pulse generator, radiating and receiving transducers with protective membranes and a selector, amplifier, first and second triggers, a switch connected by a second input to the output of the first trigger, integrator, control oscillator, frequency divider and pulse distributor connected by the first output to the input of the probe pulse generator, the second output to the second input of the second trigger and three im yield 73,842

The recorder is connected to the second input of the first trigger and the recorder connected to the output of the controlled generator; it is equipped with a delay line connected between the output of the probe pulse generator and the second input of the selector. FIG. 1 is a block diagram of the ultrasound velocity measuring device j in FIG. 2 - temporary diagrams of his work.

The device for measuring the speed of ultrasound contains a series of probe pulses, emitting 2 and receiving 3 transducers with protective membranes 4 and 5, a selector 6, an amplifier 7, first 8 and second 9 triggers, a switch 10 connected by a second input to the output of the first trigger 8 , an integrator 11, a controlled generator 12, a frequency divider 13 and a pulse distributor 14, connected by a first output to an input of a generator 1 a probe x pulses, the second output to a second input of a second trigger 9 and a third output the second input of the first triggeoa 8 connected between the, output of the generator 1 zondiruyurgih pulses and a second input of the selector 6 and the delay line 15 coupled to the output of the controlled oscillator 12 recorder 16.

The device for measuring the speed of ultrasound works in the following way,

 Control generator 12 generates a continuous sequence of pulses, which, through a frequency divider 13 with a division factor h, is fed to the input of the pulse distributor 14, which is a shift register. The pulses on each of its subsequent outputs are shifted relative to the previous output for the period of the output signal of the frequency divider 13. On the leading edge of the pulse from the first output of the distributor 14 pulses, the probe pulse generator 1 outputs a short pulse 17 to the radiating converter 2 and to the delay line 15. The emitted ultrasonic pulse propagates from the transducer 2 through the membrane 4 to the controlled medium. Get to the membrane

5 5 of the receiving converter 3, it partially reflects from the interface of the controlled medium - the material of the membrane and returns again (to 3 membrane 4 of the radiating transducer l 2. Here again it undergoes reflection from the mentioned interface of the media) echo 18 (j 1 in Fig. 2), Depending on the material and the membrane design, as well as the parameter controlled medium in the measuring section, it is possible 8-12 such reflections (i 8-12) before the practical attenuation of the sequence oh pulses. The signal from the output of the probe pulse generator 1 is delayed by a delay line 15 and opens the selector 6 by the time of arrival of the j-r reflection. From the receiving transducer l 3 is opened by the open selector 6 j and the echo pulse arrives at the input of the amplifier 7 and then goes to the input of the setup 1 the first trigger 8. The latter generates a signal 19, the leading edge of which corresponds to the moment of registration of the ith echo pulse, and the leading edge is formed on the leading edge of the pulse at the third output of the distributor 14 pulses. The signal from the output of the first trigger 8 is fed to the input of the second trigger 9, to the synchronization input of which receives a pulse 20 from the second output, the distributor 14 pulses. In this case, the second output of the distributor 14 pulses is the i-th bit of the shift register, and the third output is the K -th bit, K: i, and the equality should be observed If the time is equal to (l-1) the periods of the pulse of the divider 13 If the frequency is greater than the propagation time of the j-ro echo signal in the controller, 4 of the medium being rotated, then the output of the second trigger 9 generates a signal log. . Opened by control to the input by a signal from the output of the first trigger 8, the switch 10 connects the output of the second trigger 9 to the input of the integrator 11. The voltage at the output of the integrator 11 increases and, fed to the control input of the controlled generator 1, increases its output frequency to equality of said time intervals. If the time equal to (i - 1) periods of pulses from the frequency divider 13 is less than the propagation time of the j-th echo signal in the medium, then the operation of the device is similar, with the difference that the output of the second flip-flop 9 has a log.O signal. The input of the integrator 11 through the switch 10 is grounded for the duration of the pulse from the first trigger 8, the voltage at the output of the integrator 11 decreases, which leads to a decrease in the frequency of the controlled oscillator 11 to the fulfillment of the aforementioned equality. In the proposed device, in the steady-state mode, the arrival time j-ro of the echo-pulse in the controlled environment is equal to the time interval corresponding to its H I - 1) f) following periods of output pulses of the controlled generator, unlike the prototype, where equilibration is performed 1A periods of controlled oscillator. Using the invention allows to increase the measurement accuracy by decreasing (i - 1) times the relative error due to protective membranes.

ig.2

Claims (1)

ULTRASONIC SPEED MEASURING DEVICE, comprising probing pulse generator connected in series, emitting and receiving transducers with protective membranes, a selector, an amplifier, first and second triggers, a switch connected ... by a second input with the output of the first trigger, an integrator, a controlled generator, a frequency divider and a pulse distributor connected to the first output with the input of the probe pulse generator, the second output to the second input of the second trigger and the third output to the second input of the first three ger, and connected to an output recorder controlled oscillator, l and m of a capstan h e c i in that, in order to increase the measurement accuracy, it is provided with a delay line included between the output of the sounding pulse generator and the second input selector · SU,.,. 1137384> Figure 1