SU1640547A1 - Ultrasonic thickness gauge - Google Patents

Abstract

The invention relates to the field of non-destructive testing by an ultrasonic method and can be used for contactless measurement of the thickness of products. The purpose of the invention is to improve the measurement accuracy by automatically compensating for the effect of changes in the speed of sound. The device contains two measuring channels and a compensation channel. After a self-oscillating process is established in the compensation channel, the periodic signal generator 11 is disconnected from the converter 9. In the compensation channel, the speed of sound is converted to the frequency of the electrical signal. When a controlled article 29 is inserted between converters 2 and 5, a pulse is generated at the output of trigger 17, which is converted into a digital code using elements AND 18, a reversible counter 19 and a pulse generator 21. The trigger 24 opens the element And 26 on the signal from the output of the reversible counter 19, and the counter input of the pulse counter 27 receives pulses from the output of the amplifier 10 of the compensation channel. This provides automatic compensation for the effects of changes in the speed of sound, 2 or more.

Description

g

№21

- 2

(M + U) C

2h With

10 -C

At time g trigger 17 opens the element And 18, to another input of which receives high-frequency pulses from the output of the generator 21 pulses. Pulses Uio (t) from the output of the element And 18 (Fig. 2k) are fed to the summing input of the reversing counter 19, in which the number N0m is entered

10KA

then

ten

A 10 Ah

h

Thus, the measurement result does not depend on the ultrasound velocity in the medium, and the readings of the pulse counter 27 give a count directly in metric units D h.

The use of the invention makes it possible to increase the measurement accuracy by more than an order of magnitude due to automatic compensation of the effects of sound speed measurements.

Claims (1)

Ultrasonic device for controlling the thickness of products, containing two measuring rocks, each of which includes a series connected probe pulse generator, a transducer and amplifier, a compensation channel consisting of a reflector and a third probe generator series, a third transducer, and a third amplifier periodic signal and recorder, characterized in that, in order to improve the measurement accuracy due to automatic comp effects of changes in the speed of sound, two frequency dividers, an OR element, five AND elements, a pulse generator, two triggers, a detector, a reversible counter, a decoder, a pulse counter and a threshold element connected by the input to the detector output, and the output to the first input of the first element And, the second input of the periodic signal generator connected to the output, and the output, house - with the first input of the element PI, the output of which is connected to the input of the third probe pulse generator, the output of the third amplifier is connected to the second 5 input element OR input dstek-ora. to the first input of the second element AND s. the input of the first frequency divider soy, scientifically with the first input of the first trigger and the generator input of the alternating pulses of the first measuring channel, the output of the amplifier of which is connected to the input of the probe pulse generator, the second measuring channel, the output of the amplifier of which is connected to the first input of the third element I, connected to the second input to the decoder, the connection from the first input of the second trigger BI | HO of the third element I is connected to the second input of the first trigger, the output of the generator I / O is 20 din n to a first input "etveogoyu AND gate and a second frequency de Telem connected to the person vchotsu fifth AND gate, a second input Port, 1nenchogo with output of the second flip-flop connected to 25 to the second input of the second element I, and the output of the second element I is connected to the subtracting input of the reversing switch, the first trigger is connected to the second input to the fourth element of the fourth element 30 output-to the second input of the co- and go 1, the output of the fourth element I is connected to the summing input of the reversible counter, the outputs of which are connected to the inputs of the decoder, the output of the interlocking element AND co 35 with the counting input of the pulse counter, the output of which is connected to the input of the recorder.