SU568016A1 - Method of generating ultrasonic signal spectrum - Google Patents

Description

one

The invention relates to non-destructive testing of products and can be used in dp ultrasonic testing of products in various fields of engineering.

A known method is created by the spectrum of the ultrasonic signal, which consists in expanding the bandwidth of the searcher by changing the acoustic resistance of the damper Cl. However, this method does not provide control in a wide range of togasin products, since this significantly reduces the sensitivity of the control.

There is also known a method for creating a spectrum of an ultrasonic signal, which consists in choosing the form of the searcher's die cell depending on the spectrum required for its operation, and excites piezoelement using an electric pulse 2J. However, the amplitude-frequency characteristic of the searcher for a given configuration of the piezoelectric element remains constant and cannot be adjusted.

The purpose of the invention is to adjust the resulting spectrum. This is achieved by the fact that

The piezoelectric element excites the zones with the setting of sectional paste electrodes and changes the amplitudes of the electric components supplied to the pack.

The drawing shows the block diagram of the device that implements the method.

The device includes a skateptep containing a broadband piezoelemon 1 with electrodes; shngnkm 2, for example, solid, and the top 3 ceKunoHHpoBaHHbRi, for example, in the form of concentric rings. Each electrode 3 is connected by a wire or cable 4 to a regulating element 5, which changes the magnitude of the probe pulse, the forms of the probe pulses fed to this electrode by the generator 6. The transducer (not shown) is mounted on the surface of the product 7, the acoustic contact of which with the finder piezoelectric element is made through the contact layer 8. Each discrete zone 9 of the piezoelectric element bounded by electrodes 2 and 3 has a certain resonant frequency.

The method is carried out as follows.

Choose the form of the piezoelectric element finder in accordance with a given signal spectrum

The resulting continuous frequency spectrum is converted into discrete by sectional electrodes. The probing impulses from the pulse generator 6 are directed to the regulating elements 5, from which they go through the cables 4 to the discrete zones 9 of the piezoelectric element 1. The probing pulses excite the zones 9 of the piezoelectric element, which, through the contact layer 8, transmit mechanical oscillations of a certain frequency to the product 7. Next mechanical vibrations transformed by a piezoelectric element are fed to a spectrum analyzer (on

the drawing is not shown). With the help of elements 5, the amplitudes of the received signals of each zone of the piezoelement are established in accordance with the required amplitude-frequency characteristic, for example, uniform.

Claims (1)

Invention Formula The method of creating an ultrasound signal spectrum, which consists in selecting the form of the searcher's piezoelectric element in accordance with a given signal spectrum and exciting it with electrodes, characterized in that, in order to adjust the spectrum obtained, the piezoelectric element is excited by zones with seco-ionized electrodes and change the amplitudes electrical signal applied to the section. Sources of information taken into account in the examination: 1, A. K. Gurvich, et al. Ultrasonic inspection of welded shvov, Kiev, Technika, 1972, p. 39-4О, 45, 2, Copyright certificate № 439752, cl. Q O1 N 28/04, 1972.