SU580498A1 - Ultrasound propagation rate meter - Google Patents

Description

receiving device 6 ultrasonic pulse {FIG. 2 c) is amplified, undergoes initial processing of the sigial, as a result of which there is a time shift equal to T Te + 2tv + T7g, where To is the delay time in electrical circuits and in receiver 6, TV is the delay time in one acoustic waveguide, Tn signal delay time in the test medium.

Some of the energy of the emitted ultrasonic oscillations is reflected from the waveguide boundary — the medium under study is due to the difference in acoustic impedances of the transducer and the medium. The reflected ultrasound imimage (Fig. 2 g) is converted by the transducer into an electric one, selected by means of a temporary selector 7, and the input of the adjustable delay device 8 is available. The delay time is set to Ta. From the output of the device 8, the signal (Fig. 2 d) is fed to the second input II of the device 10 adaptive delay. The first input 9 of the device receives a signal that is shifted relative to the imimage at the second input and the time of ultrasound passing through the medium under study Tn. The time interval Tp (Fig. 2e) in the device 10 is expanded in / (times, where / C is a constant coefficient. The rising edge of the extended pulse, the duration of which is Ktn (Fig. 2g), is synchronized by the generator 1.

At the same time, the frequency of repetition of the inhibitor is determined by the relation:

Te + Kp + 2-G8

The coefficient K is chosen from the condition of f (t, g Te + 2tv in the whole range of variation of Ttg. Thus, the proposed device provides the following conversion:

I

G -

In turn, the measured time interval Tn can be represented as a function

ultrasound velocity g where / is the distance between acoustic waveguides 3 and 5. At the same time, the repetition frequency is O

F -

i.e. direct proportional signal

Ki.

Opal velocity ultrasound C in the studied medium.

The device provides a linear relationship between the ultrasound velocity in the test medium and the repetition rate of the output pulses in the presence of the device.

preprocessing of a signal in a Sihrokolce, i.e., it has a high noise immunity. When the distance between the acoustic waveguides is reduced or when the ultrasound speed increases, the linearity of the conversion is disturbed, which ensures high accuracy.

Claims (2)

Invention Formula An ultrasound velocity meter containing two ultrasonic transducers with acoustic voliovods, one of which is connected to a generator, and the other to a receiving device, characterized in that, in order to increase the measurement accuracy and no-stability, an adjustable delay device, an adaptive delay device and a pulse selector are entered in it, the first input of the adaptive delay is connected to the receiver output, the second input through the adjustable delay device and the pulse selector are connected to the generator output, and the output is connected to the generator input. Sources of information, taken into account in the examination I. USSR Copyright Certificate L 461362, cl. G 01N 29/04, 1973. 2. Kolesiikov A.E. Ultrasonic measurements. Publisher "Standard, M., 1970, p. 82