SU1408240A1 - Method of measuring velocity of ultrasound in low-absorbing media - Google Patents

Description

00yo

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1

The invention relates to a measurement technique and can be used in measuring the speed of propagation of ultrasound in molecular physics, in biophysics, in monitoring parameters of technological processes, and in ultrasound medical diagnostics.

The aim of the invention is to improve the measurement accuracy by using an auxiliary radio pulse.

FIG. 1 shows a device pea- ling a method for measuring the speed of ultrasound in weakly absorbing media; in fig. 2 shows timing charts explaining the method.

A device that implements the method of measuring the ultrasound velocity in weakly absorbing media contains, in series, the first generator 1 and the acoustic pulse emitter 2, the acoustic pulse receiver 3, located at a distance d from the emitter 2, are connected in series to the wideband amplifier 4 connected to the output receiver 3 acoustic pulse, the adder 5 and the oscilloscope 6, connected in series block 7 delay auxiliary radio pulse connected to the output of the generator 1, and the second generation p 8, whose output is connected

with the input of the adder 5, as well as block 9 delay start the sweep of the oscilloscope 6, the input of which is connected to the output of the generator 1, and the output to the second input of the oscilloscope 6.

The method is carried out as follows.

The first generator 1 excites the emitter 2 and simultaneously starts the auxiliary radio pulse delay unit 7 and the oscilloscope sweep start delay unit 9. The transmitted signal received by the receiver 3 (Fig. 2a) is amplified by a wideband amplifier 4 and added to the auxiliary radio pulse (Fig. 26) in the adder. The adjustment of the delayed start block 9 of the oscilloscope 6 sets a convenient image scale for observing the total signal.

By adjusting the delay time of the unit 7, which issues an auxiliary radio pulse, the duration of which is set in advance and chosen to be half the half period of the repulsive pulse, and the polarity is opposite to the selected half period of the restful impulse, the amplitudes of the extremes of the resulting signal are equal (Fig. 2c). The ultrasound speed is determined from the obtained delay time and the known distance.

Claims (1)

A METHOD FOR MEASURING THE ULTRASOUND SPEED IN WEAKLY ABSORBING MEDIA, which consists in emitting and receiving an acoustic pulse that has passed a fixed distance in the medium under study, characterized in that, in order to increase accuracy, the duration and polarity of the selected half-cycle of the pulse transmitted through the medium under study are measured, and a delayed relative to the moment of radiation an auxiliary radio pulse, the duration of which is equal to half the half-period of the transmitted pulse, and the polarity is opposite to the selected floor Heat-transmitted pulse, the delay is adjusted until the auxiliary rf pulse combining it with a selected half cycle of the transmitted signal, wherein the registration is performed two extreme values with equal amplitudes and the measured value of delay with the base sounding determined length required parameter. Figure 1