SU859811A1 - Ultrasonic thickness gauge - Google Patents

Description

(54) ULTRASOUND THICKNESS MEASURES

The invention relates to non-destructive ultrasonic testing and can be used to measure the thickness of articles made of various materials. A known ultrasonic thickness gauge comprising a probe pulse generator, a transducer, a trigger, a selection unit, a delay unit, a square pulse former, a coincidence circuit, and a trigger p. The disadvantage of this thickness gauge is low accuracy and measurement performance due to manual adjustment of the instrument. The closest to the technical essence and the achieved result is an ultrasonic thickness gauge containing a synchronously connected synchronizer, a receiving-transmitting unit, a counter, the second input of which is connected to the output of the synonizer, the selection pulse generator, the time selector, the second input of which is connected to the output of the receiving and transmitting unit, the meter, the second input of which is connected to the output of the synchronizer, and the recorder 2. The disadvantage of this thickness gauge is low accuracy This is because the interfering signals can be present between the sequence of these pulses, and the measurement performance is low due to manual tuning to a specific reflected pulse. The purpose of the invention is to improve the performance and accuracy of measurements. The goal is achieved by the fact that the ultrasonic thickness gauge is connected between the receiving-transmitting unit and the counter, connected in series by the pulse shaper Ban, the second input of which is connected to the synchronizer output, the OR circuit and the delay circuit, the transducer duration - amplitude, the first input of which is 585981

It is connected to the synchronizer output, the second stroke is to the output of the pulse generator Disabling, and the transducer implies the duration, included between the transducer, the duration - j amplitude, and the OR circuit and connected to the output of the delay circuit.

The drawing shows a block diagram of an ultrasonic thickness gauge.

Ultrasonic thickness gauge contains 10 serially connected synchronizer 1, receiving and transmitting unit 2, shaper 3 pulses Prohibition, the second input of which is connected to the output of synchronizer 1, circuit A OR, is the delay circuit 5, counter 6, the second input of which is connected to the output of synchronizer 1, generator 7 of selective pulses, time selector 8, the second input of which is connected to the output 20 of the receiving and transmitting unit 2, time indicator 9, the second input of which is connected to the synchronizer output, and the recorder 10. To the synchronous output A mash is also connected to a transducer of duration - amplitude 11, the second input of which is connected to the output of the pulse shaper Disable. Between the converter duration-amplitude 11 and the circuit 4 OR the transducer has an amplitude of duration 12, the second input of which is connected to the output of the delay circuit 5.

Ultrasonic thickness gauge works as follows.35

The sync pulses from the output of synchronizer 1 start the generator (not shown), included in the receiving and transmitting unit 2. The pulses from this block are sent to the pulse shaper 3 The inhibitor, which forms the first impulse from the ban by temporal selection of the surface and first given pulses . The inhibit pulses come through the circuit 4 OR to the input 5 of the delay circuit 5, which, triggered from the trailing edge of this pulse, produces a delay pulse equal in duration to the first bottom echo pulse. Pulses from the output of the generator of 3 pulses The prohibition also goes to the input of the converter 11 duration-amplitude, which transforms the pulse duration into a proportional voltage value of 55. Resetting the transducer 11 duration-amplitude in each clock cycle

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sync pulses are carried out by the falling edge of the pulse from the front face The pulses from the output of the duration-amplitude converter 11 are fed to the control input of the converter 12 amplitude-duration, which is triggered by the falling edge of the pulses from the output of delay circuit 5. As a result, pulses are formed whose duration is equal to the duration of the first inhibit pulse. The pulses go to the second input of circuit 4 OR, and the whole process repeats. As a result, a sequence of pulses is formed, during periods of which the time selector 8 is closed. The pulses from the output of the delay circuit 5 are fed to the input of the counter 6, which is reset to the initial state by the second input by the pulses from the output of the synchronizer 1.

By setting the necessary conversion factor for counter 6, you can select any pulse from a series of bottom pulses for use in measuring the propagation time of ultrasound in materials. The selection pulse generator 7 generates a pulse equal in duration to the bottom pulse, which is turned on by the time selector 8. Time meter 9 measures the time interval between the sync pulse and, for example, the fifth bottom pulse. The measurement results are displayed by the recorder 10.

Thus, the proposed thickness gauge allows automatic projection of bottom echo pulses resulting from the reverberation of ultrasonic oscillations in the sample, regardless of the base to be measured and ultrasound velocity in the material, which makes it possible to increase the productivity and accuracy of measurements.

Claims (2)

1. Author's certificate of the USSR 187321, cl. G 01 B 17/02, 1962. 2. Authors certificate of the USSR 149573, cl. G 01 B 17/02, 1962. (prototype).