SU1439411A1 - Method of determining velocity of propagation of ultrasound oscillations in melts - Google Patents

Abstract

The invention relates to non-destructive testing and can be used to measure the elastic properties of liquid media under high pressure and temperature. The purpose of the invention is to increase the measurement accuracy by taking into account the redistribution of the temperature field. The method consists in that ultrasonic pulses are emitted in the acoustic cell containing the mobile and fixed waveguides and the layer of the liquid under study between them, receive the transmitted and once reflected pulses, change the position of the movable waveguide and measure the propagation times of the ultrasonic pulses transmitted through the acoustic cell and once reflected in the MOBILE waveguide, before and after moving the waveguide. Moreover, measurements are made after the establishment of a stationary temperature field. 1 pe. )

Description

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The invention relates to non-destructive Koitrrponw materials and can be used to measure the elastic properties of liquid media under high temperature or high pressure and to analyze corrosive media.

The purpose of the invention is to increase the accuracy of measurements by taking into account the redistribution of the temperature field.

The drawing shows a diagram of an apparatus for determining the speed of propagation of ultrasonic vibrations in melts and the propagation of ultrasonic vibrations in its elements.

A device for determining the speed of propagation of ultrasonic oscillations in melts contains coaxially located 1 and not 2 pinwelled waveguides, the opposing ends of which are immersed in the melt 3, to the free ends of the waveguides from the heating 25

devices 4; installations; connecting with acoustic contact; radiation 5; and a German 6 transducer. Positions 7 and 8 denote respectively passing directly through the ultrasonic and ultrasonic cell, (polys and impulse, once reflected in the moving waveguide 1).

The method for determining the rate of dispersion of ultrasonic vibrations in melts is carried out as follows.

Using a radiating transducer 6 in the waveguide 2, a pulsed ultrasonic oscillation is generated, which propagates through the layer of the substance being monitored and the waveguide 15 reflects from the plane-parallel boundaries of the waveguides. In the case of monitoring media with high absorption, when no echo pulses form in the melt zone, the ultrasonic transducer 5 receives a direct pulse 7 and an echo pulse from the waveguide, from which the first echo pulse 8 from the mobile waveguide is used for control. , applied to receiver transducer 5,

The time t of propagation of the transmitted pulse 7 and the time t of the once impulse pulse 8 are measured, after which the moving waveguide 1 is transited.

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placed at a distance of 41 and after the stationary temperature field is established in it, the propagation times of the transmitted and once reflected pulses, t and t, are measured again.

The speed of propagation of ultrasonic vibrations is determined by the formula

g - - - 73 (t-fc) - () /

To prevent echo pulses from both waveguides from coinciding in time, waveguides 1 and 2 should be made of different lengths. It is enough, for example, lengths 1, and f, respectively, of waveguides I and 2 to choose short-circuit conditions 1.1, - 31 and C ,, where 1 is the duration of the ultrasonic pulse; C is the speed of sound in the sound duct material.

Invention Formula

The method of determining the speed of propagation of ultrasonic oscillations in melts, which consists in emitting ultrasonic oscillation pulses into an acoustic cell containing mobile and stationary waveguides and a layer of melt between them, receives the transmitted and reflected from the boundary of the mobile waveguide with the ultrasound melt the t pulses, measure the times t and t, their propagation, move the movable waveguide to the distance dl, measure the propagation time t of the transmitted pulse after moving the movable waveguide taking into account the measured propagation times of the pulses, the velocity of propagation of ultrasonic oscillations, characterized in that 5 in order to improve measurement accuracy by taking into account the redistribution of the temperature field, the propagation time tj of the ultrasonic pulse reflected from the boundary of the movable waveguide with the melt after moving the movable waveguide and establish a stationary distribution of the temperature field in it, and the speed of propagation of ultrasonic vibrations determine according to the formula

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/ 3 (t-t) - (t, -, ti) 7

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Claims (1)

Claim The method for determining the propagation velocity of ultrasonic vibrations in melts, which consists in emitting ultrasonic pulses into an acoustic cell containing a movable and stationary waveguides and a melt layer between them, receive ultrasonic pulses transmitted and reflected from the boundary of the movable waveguide with the melt, measure the times t and t _(their distribution, the movable waveguide is moved by a distance 41, measured propagation time t ¹ after the transmitted pulse and the movable waveguide op taking into account the measured propagation times of the pulses, · the propagation speed of ultrasonic vibrations, characterized in that, in order to increase the accuracy of measurements by taking into account the redistribution of the temperature field, they additionally measure the propagation time of the ultrasonic pulse reflected from the boundary of the moving waveguide with the melt after moving the moving waveguide and establishing stationary distribution of the temperature field in it, and the propagation velocity of ultrasonic vibrations is determined by the forms ole c = / 3 (tt ^, ) “-“ (trt'p7 ' 1 439411