SU868351A1

SU868351A1 - Ultrasonic method of measuring article coating thickness

Info

Publication number: SU868351A1
Application number: SU802861747A
Authority: SU
Inventors: Анатолий Павлович Застава; Александр Владимирович Нестеров
Original assignee: Предприятие П/Я Р-6209
Priority date: 1980-01-02
Filing date: 1980-01-02
Publication date: 1981-09-30

Description

(54) УЛЬТРАЗВУКОВОЙ СПОСОБ ИЗМЕРЕНИЯ ТОЛЩИНЫ ПОКРЫТИЙ ИЗДЕЛИЙ(54) ULTRASONIC METHOD FOR MEASURING THE THICKNESS OF PRODUCT COATINGS

1one

Изобретение относитс к измерительной технике и может быть исполь зовано дл измерени толщины защитных покрытий.The invention relates to a measurement technique and can be used to measure the thickness of protective coatings.

Известен ультразвуковой способ измерени толщины покрытий, основанный на зависимости затухани поверхностных волн от толщины покрыти tij.A known ultrasonic method for measuring the thickness of coatings is based on the dependence of the attenuation of surface waves on the thickness of the coating tij.

Недостатком указанного способа вл етс низка точность, обусловленна трудност ми при измерении толщины покрыти с высоким затуханием.The disadvantage of this method is low accuracy due to difficulties in measuring the thickness of the coating with high attenuation.

Наиболее близким по технической сущности к предлагаемому вл етс ультразвуковой способ измерени : толщины покрьпнК. изделий, заключающийс в том, что устанавливают на изделие со стороны покрыти излучатель ультразвуковых колебаний, ввод т с его помощью в изделие ультразвуковой импульс с широким спектром частот, принимают отраженные сигналы, анализигуют спектр эхо-сигналов и по. изменени м параметров спектра суд т о толщине C IНедостатком известного способа вл етс низка точность измерени покрытий малой толщины, обусловленна сложностью выделени измер емой части эхо-сигнала.The closest in technical essence to the present invention is an ultrasonic method of measurement: the thickness of the rivet. products, which consist in installing an emitter of ultrasonic vibrations on the product from the coating side, inserting an ultrasonic pulse with a wide frequency spectrum into the product, receiving reflected signals, analyzing the spectrum of the echo signals and. Changes in the spectrum parameters are judged on the thickness C. The disadvantage of this method is the low measurement accuracy of thin coatings, due to the difficulty in extracting the measured part of the echo signal.

Цель изобретени - повышение точности измерени покрытий малой толщины .The purpose of the invention is to improve the measurement accuracy of coatings of small thickness.

Поставленна цель достигаетс тем, 5 что располагают между излучателем ультразвуковых колебаний и покрытием слой материала с волновым сопротивлением , равным отношению квадрата .волновому сопротивлению покрыти 0 к волновому сопротивлению издели , вьщел ют эхо-сигнал, отраженный от поверхности покрыти , и по первому частотному минимуму огибающей частотного спектра суд т о толщине 15 измер емого покрыти , которую определ ют из выражени СThe goal is achieved by the fact that between the emitter of ultrasonic vibrations and the coating there is a layer of material with a characteristic impedance equal to the ratio of the square wave resistance of the coating 0 to the characteristic impedance of the product, the echo signal reflected from the surface of the coating the frequency spectrum is judged to be a thickness of 15 measurable coatings, which is determined from the expression C

(1)(one)

где d - толщина измер емого пок20 рыти ;where d is the thickness of the measured surface;

Claims

C is the propagation velocity of the Ultrasonic vibrations in the coating being measured, f is the frequency of the pervrgo. minimum 25 energy spectrum of the echo signal reflected from the surface of the coating -. The angle of propagation of ultrasonic vibrations in 30 controlled products. The method is carried out as follows. In the product from the side of the measured coating through a layer of material with an impedance determined from the expression Zg, where Z is the characteristic impedance of the layer of material through which the ultrasonic vibrations are introduced into the product; Z. - wave impedance and ii9j tasks, ultrasonic vibrations introduced by a short pulse with a wide frequency spectrum, a temporary pulse generator of radio pulses, are emitted by an echo signal reflected from the surface of the digging and This is the type of coating being measured, which is determined by formula (1). Thus, the proposed method allows accurate determination of the coating thickness of the products. The invention Ultrasonic method for measuring the thickness of the coating of products, I conclude that an emitter of ultrasonic vibrations is installed on the product from the coating side, a ultrasonic pulse with a wide frequency spectrum is inserted into the product, the echo signals are analyzed, and the echo signals are analyzed and according to the changes in the spectrum parameters, the thickness is judged, characterized in that, in order to improve the measurement accuracy of the coating of small thickness, a layer is placed between the emitter of ultrasonic vibrations and the coating Material with an impedance equal to the ratio of the square impedance of the coating to the characteristic impedance of the product is extracted. An echo signal reflected from the surface of the coating and. . 4fco; v where d is the thickness of the coating being measured. ty, C is the propagation velocity. ultrasonic vibrations; in the measured coating; - frequency of the first minimum of the energy spectrum of the echo signal reflected from the surface of the coating; - the angle of propagation of ultrasounds. Vukovyh fluctuations in a controlled product. Sources of information taken into account in the examination 1. The author's certificate of the USSR 198691, cl. G 01 B 17/02, 1966.

2. USSR author's certificate number 389401, cl. G 01 B 17/02, 1971 (prototype).