SU1345109A1 - Receiving section of ultrasonic flaw detector - Google Patents

Abstract

The invention relates to non-destructive testing and can be used in ultrasonic devices and installations for the flaw detection of materials and products of the metallurgical, engineering, energy and other industries. The aim of the invention is to increase the reliability of the control due to the detuning from acoustic and structural interference in the entire dynamic range of the amplitudes of the echoes. A digital amplitude-time selector is introduced into the receiving path of the ultrasonic flaw detector, consisting of a code comparison circuit 4, 5 selection levels RAM, and 10 time intervals counter. Formed by the stepwise approximation method in the amplitude-time selector by a RAM block of 5 selection levels under the control of a counter of 10 time intervals and a computer 9, the temporal dependence of the selection level of the range of the analyzed echoes from the time of their distribution in the tested product is fed to the first input of the code comparison circuit 4 where, when the amplitude of the input signals is exceeded, from AChG 3, in the corresponding area of the control zone, the transmission resolution signal at the output of the personal n-digit code of measured by Cheney useful echo signal amplitude 1 yl. from 03 4: sd

Description

The invention relates to non-destructive testing and can be used in ultrasonic surfs and installations for the flaw detection of materials and products in the metallurgical, engineering, energy and other industries.

The aim of the invention is to increase the reliability of control due to the detuning from acoustic and structural interference in the entire dynamic range of variation of the amplitudes of the echo signal.

The drawing shows a structural diagram of the receiving path of the ultrasonic flaw detector.

The device contains a series-connected electroacoustic transducer 1, a pre-amplifier 2, an analog-digital converter (ASCH1) 3, a code comparison circuit 4, a second input connected to the output of a random access memory (RAM) 5 selection levels, a circuit 6 for maximal division, the first input connected to the first output of the control device 7, a buffer storage device 8, a second input connected to the first output of the control device 7, an electronic computer (computer) 9, the first RAM input 5 levels of selection is connected to the output of the counter. 10 time intervals, the first input of the counter 10 time intervals are connected to the second output of the control device 7, and the second inputs of the counter 10 time intervals and the RAM 5 of the selection levels are connected to the output of the computer 9. The serially connected counter of 10 time intervals, the RAM 5 levels of the selection and Scheme 4 Comparison forms a block of amplitude-time selection.

The computer 9 contains a random access memory 11, a parallel interface 12, a central processor 13, a channel 14, a persistent storage device 15, a serial exchange device 16, a display 17. The device operates as follows.

The signals reflected from the defect or the bottom of the product are taken by converter 1, converted into electric, placed in preamplifier 2, and fed to information input of analog-digital converter 3. Digitized n-bit amplitudes of input signals

all dynamic range equal to

2, are fed to the input I of the code comparison circuit 4 (where n is the number of bits A1D1).

In the amplitude-time selector by the method of linear-piecewise approximation is formed under computer control, 9 the dependence of the selection level of the range of the analyzed echo signals on

the time of their propagation in the controlled product and the extraction of useful signals by comparing the amplitudes of the echo signals in the digital code from the ADC 3 in this digital code with this dynamic level.

From the sequence of clock pulses, arriving at input 1 of the counter 10 time intervals from the control device 7, in the counter 10

time intervals under the control of the computer 9, sampling intervals are formed in time of the level of selection of the range of the analyzed echo signals applied to the input I of the code comparison circuit 4. The whole sampling range T is determined by the duration of the strobe (control zone) coming from the control device 7. Through the formed; intervals

sampling, affecting the RAM control input of 5 amplitude-time selector selection levels, a sequential recording of quantization intervals set by the amplitude level of the analyzed echo-signals is set. Range

quantization is equal to the range of changes in the amplitudes of the echo signals, i.e. 2

The values of quantization intervals by amplitude, sampling intervals in time and their total number are selected depending on the required law of variation of the limiting sensitivity of the 5scop defect in the depth of control (for example, depending on the type of converter, the material of the product being tested, etc.) and the specified accuracy his work

The temporal dependence of the selection level formed by the step interpolation method is fed to the second input of the comparison circuit 4

the amplitude-time selector codes X, where, when the amplitude of the input signals is exceeded: signals from the ADC 3 selection levels in the corresponding area of the control zone, a transmission resolution signal is generated at the output of the full n-bit value of the measured amplitude of the echo signal.

The signals from block 6 using block 7 of the control are recorded in a high-speed buffer memory 8. Block 8 provides buffering of the data set after preprocessing in connection with the need to reconcile the high speed of the ultrasonic monitoring information and the relatively low intensity of data transmission in the computer 9.

Using the control unit 7, the accumulated information is sampled from the buffer memory 8 and transmitted to the computer 9 for further processing at the program level and displaying on the display (or other peripheral device).

The use of an amplitude-time selection scheme for echo signals allows p (to realize dynamic detuning from structural and acoustic interference over the entire measurement range of the depth of the flaw detector, which leads to I.Ardasheva compiler Editor A.Povkhan Tehred M.Didyk Corrector

Order D913 / 43 Edition 775 Subscription

VNISHI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, st. Project, 4

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Claims (1)

the reliability of the ultrasound control. Invention Formula The receiving path of an ultrasonic flaw detector containing a series-connected electroacoustic transducer, a preamplifier and an analog-digital converter, a maximum extraction circuit, a buffer memory and an electronic computer (computer), a control device, the first output connected to the first input of the maximum circuit and to the second the input of the buffer memory device, characterized in that, in order to increase the reliability of the control, it is provided with amplitude-time a selector made of serially connected time interval counter, random access memory (RAM) of the selection levels and code comparison circuit, the first input of the time interval counter connected to the second output of the control device, the second inputs of the time counter and the selection level RAM being connected to the computer output , the second input of the code comparison circuit is connected to the output of the analog-digital converter, and the output is connected to the second input of the maximum allocation circuit.