SU811079A1

SU811079A1 - Method and apparatus for determining ultrasound propagation speed

Info

Publication number: SU811079A1
Application number: SU782582552A
Authority: SU
Inventors: Армен Паруйлович Сарвазян; Аркадий Абрамович Зарецкий
Original assignee: Институт Биологической Физики Анссср
Priority date: 1978-02-20
Filing date: 1978-02-20
Publication date: 1981-03-07

Description

При помощи аттенюатора 4 и перестраиваемой линии 6 задержки подби1рают услови возни:кновеи« автоколебаний Б замкнутой |Цепи, что контролируетс дискриминатором 9, измер ют частоту автоколебаний частотомером 7, затем мен ют положение ключа J1, при котаром в замкнутую цепь включаетс фазои.нверто1р 10, который измер ет сдвиг фазы на 180°. Снова измерйют частоту . Разность измеренных частот однозначно -св зана со скоростью ультразвука в исследуемой среде соотношениемА/ V/21,Using an attenuator 4 and a tunable delay line 6, the following conditions are created: the new self-oscillations of the B closed | circuit, which is controlled by the discriminator 9, the frequency of the self-oscillations is measured by the frequency meter 7, then the key J1 is switched to , which measures a phase shift of 180 °. Measure the frequency again. The difference in the measured frequencies is unambiguously connected with the ultrasound velocity in the studied medium by the ratio A / V / 21,

где А/ Уwhere a / u

разность измеренных частот; скорость ультразвука в исследуемой среде;the difference between the measured frequencies; ultrasound velocity in the test medium;

/ /

рассто ние между приемным и излучающим преобразовател ми .distance between receiving and radiating converters.

П|реИМуществО|М способа и уст1ройства дл его осуществлени вл етс однозначность отсчета скорости распространени ультразвука в широком диапазоне значений скоростей при сохранении высокой точности измерений «по 1сравнеаию с известным устройством.The PIME | M method and device for its implementation is the unambiguity of counting the propagation speed of ultrasound in a wide range of velocity values while maintaining high measurement accuracy in comparison with the known device.

Claims

1. A method of measuring the speed of propagation of ultrasound by creating auto-oscillations in a closed electric field, including an acoustic chamber, and measuring the frequency of these oscillations, characterized in that, in order to determine the speed of ultrasound, the phase of the electrical signal is inverted; frequency, and ultrasound velocity is determined by the difference in measured frequencies.

2. An apparatus for carrying out the method according to claim 1, comprising a series-connected acoustic chamber with a receiving and radiating electroacoustic transducers, an attenuator, a bandpass amplifier, a tunable delay line, and a frequency meter and amplitude detector connected to the output of the amplifier, the output of which is connected to a discriminator, from the fact that it is equipped with a phase inverter, turned on or off with a key and located in the electrical circuit.

Source of information taken into account in the examination:

1. USSR author's certificate No. 437008, cl. G 01 N 29/00, 1972 (prototype).

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