SU920396A1 - Device for measuring speed of ultrasound - Google Patents

Description

(54) DEVICE FOR MEASURING SPEED

I

The invention relates to a measurement technique and is used to measure the acoustic characteristics of various materials.

A device for measuring the speed of ultrasound is known, comprising a selection pulse generator, a recorder and a synchronizer connected in series, a pulse generator, an emitting transducer, acoustically coupled through the material under study with the receiving transducer, an amplifier, a time selector, the second input of which is connected to the output of the selector generator pulses, the code of which and the recorder input are connected to the synchronizer output, and the output of the time selector - to the additional input m 1 registrar.

A disadvantage of the known device is nev | 1 low measurement accuracy due to the limitation of the signal spectrum and the change in attenuation in the material under study under the influence of extra factors. ULTRASOUND

The goal of the ebb is to increase measurement accuracy.

This goal is achieved by the fact that the device is equipped with a unit for automatically installing a spectrum of spectral components of a signal consisting of an adder and parallel-connected channels, each of which is sequentially connected narrow-band filters, amplifiers with an adjustable amplification factor, detectors and amplifiers of direct current, whose outputs and the output of the adder is connected to the recorder, the inputs of the adder are connected to the outputs of amplifiers with an adjustable gain factor, the control inputs of which are connected the outputs gradual current amplifiers and the inputs of filters uzkopolosnos yield BpeMeiraoro selector.

In the drawing, a block diagram of the us20 mode for the speed of ultra sound is muffled.

Claims (2)

The device contains a selection pulse generator 1, a recorder 2 and a synchronizer 3 connected in series, a generator of 4 excitation pulses, an emitting transducer 5, connected through the material 6 under test with the receiving transducer 7, an amplifier 8, a time selector 9, the second input of which is connected to the output of the generator 1 of the selection pulses, the input of which and the input of the recorder 2 are connected to the output of the synchronizer 3. The device is equipped with a unit U of automatic installation of the level of spectral components a signal consisting of an adder 11 and. parallel-connected channels, each of which contains successively included narrowband filters 12 and 13, amplifiers 14 and 15 with an adjustable gain factor, detectors 16 and 17, amplifiers 18 and 19 dc, whose outputs and the output of the adder are connected to the recorder 2, the inputs of the adder 11 are connected to the outputs of amplifiers 14 and 15 with adjustable amplification factor, the control inputs of which are connected to the outputs of amplifiers 18 and 19 of direct current, and the inputs of narrow-band filters 12 and 13 to the output of th selector belt 9. The device operates as follows. Video pulses from synchronizer 3 start the generators 1 and 4 of the selection pulses, and also go to the recorder 2. From the output of the excitation pulse generator 4, a radio pulse arrives at the radiating transducer 5 and through the material under study 6 to the receiving transducer 7, from which a poio electric signal, which is a series of radio pulses corresponding to the successive reflections of the acoustic signal in the test material 6, after the gain in the amplifier 8 is fed to a schiamennaya sector 9, the second input of which from the generator output 1 of the selection pulses receives a selection pulse, From the output of the selector 9, a radio pulse, respectively Corresponding to any reflection of the acoustic signal, it enters narrow-band filters 12 and 13 of the unit Yu of the automatic installation of the level of the spectral components of the signal. The number of filters 12 and 13 is chosen so that they completely overlap the frequency band of the incoming signal. The bandwidth of the filters is selected based on the permissible magnitude of the measurement error. From the outputs of the filters 12 and 13, the signals are fed to amplifiers 15 and 14 with adjustable gain, and from their output to the detectors 16 and 17 and the adder 11. The constant constant voltage allocated after the detectors 16 and 17 is amplified into the amplifier x 18 and 19 of direct current and fed to the regulating inputs of amplifiers 14 and 15. Thus, at the output of each amplifier 14 and 15, we obtain a constant specified value of the amplitude of a separate spectral component of the signal, independent of the amplitude of the signals supplied to the inputs of the amplifiers 14 and 15. At the exit from mmatora 11 after summing all spectral components receive the original signal, but with constant values of spectral components. This signal enters recorder 2 and is used to measure the speed of propagation of ultrasound. From the outputs of the amplifiers 18 and 19, the voltage is also fed to the recorder 2, where they can be used to set the required level of individual spectral components of the signal or to measure the attenuation in the material under study. Thus, in the proposed device, the recorder uses an electrical signal from the output of the adder 11 and has a constant amplitude and spectral characteristics, which creates a significant increase in measurement accuracy compared to existing devices. In addition, the automatic setting of the amplitude of the spectral signals of the signal makes it possible to measure with high accuracy the current values of the ultrasound velocity in materials in which the attenuation coefficient is measured in terms of frequency. The formula of the invention apparatus for measuring comprising selektriukadih pulse generator uptrazEuia speed recorder and p6sledovvtevhno included synchronizer voobuzhdakptsih pulse emitting preo6 razo vatep sonically bondable through the test material to a receiving tfeobrazovatepem, power, time selector, the second input of which soedashen yield sepektyruk generator pkhh pulses, the input of which and the input of the registrach-ora are connected to the output of the synchronizer, which is oticha; that, with a precision measuring circuit, it is equipped with an automatic unit for setting the level of the spectral composition of the signal, consisting of an adder, and parallel-connected channels, each of which contains after-bandwidth narrowband filters, variable gain amplifiers, detectors and constant amplifiers, the outputs of which and the output of the combinator are connected to the recorder, and the modulator 92 6 are connected to the outputs of amplifiers with adjustable gain, the control inputs of which Connections are connected to the outputs of the DC amplifiers, and the inputs of the narrow-band filters are connected to the output of the time selector. Sources of information taken into account in the examination: 1. Maksimov V.N. A pulse-phase setup with improved signal compensation for measuring the velocity of ultrasonic waves. - Sat. Far East: acoustic collection, vol. 2, Vyadivo current 1976, p. 1OE-111 (prototype).