RU2130610C1 - Digital ultrasonic flaw detector avgur - Google Patents

Abstract

FIELD: instrumentation, ultrasonic flaw detection. SUBSTANCE: to generate image of tested section and to measure dimensions of defect directly flaw detector is supplemented with former 13 of scan of B type, former 17 of VRCH- characteristic and former of ARD- diagram controlled through control unit 1 coupled with inputs to permanent storage 19 and with outputs - to display 12. Preprocessing unit 8 fabricated in the form of filtration circuit 10, circuit of extraction of envelope and commutator that provides for various transmission of signal from amplifier 7 to analog-to digital converter 9 through these circuits which is placed between amplifier 7 and analog-to-digital converter 9. EFFECT: enhanced operational reliability and efficiency of flaw detector. 1 cl, 2 dwg

Description

 The invention relates to instrumentation and can be used for ultrasonic flaw detection, research, methodological and educational work.

 Known ultrasonic flaw detector [1], containing a serially connected synchronizer, an ultrasonic oscillation generator, a piezoelectric transducer, an amplifier and an automatic defect signaling device, an indicator, amplifier control units, a frequency response unit, a strobe block of an automatic defect signaling device, etc. Using a flaw detector allows you to pre-configure for any number of control programs, that is, to increase the performance of the control, and does not require reconfiguration of the flaw detector when changing the object of control or the stage of control of the object.

 The disadvantages of this flaw detector are the inability to study the spectrum of received echo signals in real time, insufficient noise immunity, the inability to control products of large thickness and materials with an increased attenuation coefficient.

 A known digital ultrasonic flaw detector [2], comprising a control unit, a probe pulse generator, a switch, an attenuator and a preamplifier connected to the switch with an ultrasonic transducer, an ADC unit, a buffer memory unit, an accumulation unit and a reflection unit, a time averaging unit, a digital filtering unit, spectral analysis unit. The device also contains a programmable storage device (ROM), in which the necessary parameter values are pre-entered.

 Its disadvantages are the impossibility of obtaining an image of a controlled section, the absence of a temporary adjustment of sensitivity, which does not allow directly measuring the equivalent dimensions of the defect.

 These disadvantages are in a well-known technical solution containing a control unit connected to one of its outputs and sequenced in series, a probe pulse shaper, a switch, the second input of which is connected to one of the control unit outputs, and an amplifier connected to the switch by an ultrasonic transducer, each connected to the corresponding output of the control unit and the ADC unit, the buffer memory unit, the accumulation unit and the display unit interconnected in series, the outputs of the accumulator units The buffer unit and the buffer memory unit are connected with the corresponding inputs of the control unit, the time averaging unit, the inputs of which are connected respectively to the second output of the buffer memory unit and one of the outputs of the general control unit, and the output is connected to the third input of the accumulation unit, a digital filtering unit included between the corresponding the output of the control unit and the third input of the display unit, a spectral analysis unit connected to the output of the control unit, the output of which is connected to the fourth input of the display unit, programmer a memory device (ROM), the output of which is connected to the second input of the digital filtering unit, the second input of the amplifier is connected to the output of the control unit, is eliminated due to the fact that the digital ultrasonic flaw detector is equipped with a B-type scanning imager (in brightness form) connected to the control input with a control unit, and the output - to the fourth input of the accumulation unit, a pre-processing unit connected to a separate output of the control unit and connected between the amplifier and the ADC unit, the SHF-driver amplitude and distance - diameter (ARE) connected to the corresponding outputs with the fifth and sixth inputs of the display unit, the second inputs with the corresponding outputs of the ROM, and the amplifier is made with a controlled gain control circuit.

 And also due to the fact that the pre-processing unit is made in the form of a filtering circuit, an envelope allocation circuit and a switch designed to connect these circuits to the amplifier and the ADC unit.

 Figure 1 presents a block diagram of a flaw detector; figure 2 is a block diagram of a block of pre-processing.

 The flaw detector contains a control unit 1, sequencer 2 connected in series, probe pulse generator 3, switch 4, ultrasonic transducer 5, the output of which through attenuator 4, attenuator 6, amplifier 7, pre-processing unit 8, ADC unit 9, buffer unit 10 are connected in series memory, the accumulation unit 11 and the display unit 12. The B-type scan driver 13 is connected to the output of the control unit 1, and its output is connected to the input of the accumulation unit 11. A temporary averaging unit 14 is connected to the individual outputs of the control unit 1, having an input from the input of the buffer memory unit 10 and an output to the input of the accumulation unit 11, and a digital filtering unit 15, the output of which is connected to the input of the display unit 12. A spectral analysis unit 16 is included between the control unit 1 and the display unit 12.

 The shaper of the RF characteristics and the shaper 18 of the ARD diagram are also included between blocks 1 and 12, and the block 19 of the ROM is connected by its outputs to the shapers 17 and 18 and the block 15 of digital filtering. The pre-processing unit 8 contains a filtering circuit 20, an envelope allocation circuit 21, and a switch 22 connecting them to the flaw detector.

 The device operates as follows.

 Before starting work, the ultrasonic transducer is located on the surface of the controlled material or product. In the process, the control unit 1 organizes periodically repeated execution of the measuring cycles. The operating modes of blocks 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18 are also set from the control unit 1, the cycle starts with the control unit 1 starting sequencer 2, which generates binary paraphase sequence of pulses arriving at the output pulse shaper 3. The generated electrical sounding signal through the switch 4 is fed to an ultrasonic transducer (USP) 5, which converts it into an ultrasonic wave emitted into the control object. Received acoustic echoes are converted using USP 5 into an electrical signal that enters through the switch 4 and attenuator 6 to the input of amplifier 7. The amplifier 7 pre-amplifies the signal, sets the total gain and the law of change in gain over time using block 1 ( ASU). The preprocessing unit 8 can operate depending on the commands of the control unit 1 in several modes: either in the case of using broadband signals, it transfers the signal from amplifier 7 to ADC unit 9, or this signal is transmitted through switch 22 to the envelope extraction circuit 21 and thus detected the signal through the same switch 22 is fed to the ADC block 9, or, for conventional signals, through the switch 22 to the filtering circuit 20, where band-pass filtering is carried out, corresponding to the frequency range of the used USP 5, and ATEM through the switch 22 - to the block 9 ADC.

 In block 9 of the ADC, the incoming signals are converted into a sequence of binary multi-bit samples, which are transmitted for accumulation to block 10 of the buffer memory. After the buffer memory is completely filled with samples of the input signal, the control unit 1 completes the measurement cycle by transmitting the contents of the buffer memory to the input of the temporary averaging unit 14, where the signals are averaged and transmitted to the accumulation unit 11. At the same time, according to the signal from the control unit 1, the B-type scan driver 13 supplies periodic signals to the fourth input of the accumulation unit 11, where an array of data corresponding to the B-type scan, which is displayed in the display unit 12, is generated.

 In block 16 of the spectral analysis, through the control unit 1, a signal is received from the buffer memory unit 10, where the spectrum of the echo signal is calculated in real time and then transmitted to the display unit 12.

 If necessary, from the buffer memory unit through the control unit 1, the signal enters the digital filtering unit 15. Together with the echo signal from block 1, a command is sent to select a certain type of information embedded in ROM 19 (namely, the impulse response of the SPD 5 currently in use).

 From block 11 accumulation through block 1, the signals are either transmitted to the shaper 17 of the RF characteristic, where, on command from block 1, ROM 19 receives information regarding environmental parameters. Shaper 17 generates an RF characteristic. Additionally, from the block 10 of the buffer memory, the current echo signal is taken, multiplied by the generated RF characteristic and goes to the display unit 12. Or, the signals from block 11 accumulation through block 1 are fed to the shaper 18 ARD-chart. In this block, taking into account the necessary data requested from the ROM 19, an ARD diagram is generated, which is fed to the display unit 12, where it is superimposed on the image of the echo signals.

 Thus, the use of this digital ultrasonic flaw detector, among other things, allows you to get an image of a controlled section, to provide temporary adjustment of sensitivity, that is, to obtain directly measured equivalent defect sizes.

Claims (2)

 1. A digital ultrasonic flaw detector containing a control unit connected to one of its outputs and sequentially connected, a probe pulse shaper, a switch, an attenuator, the second input of which is connected to one of the control unit outputs, and an amplifier connected to the switch by an ultrasonic transducer, connected each to the corresponding output of the control unit and an analog-to-digital converter, a buffer memory unit, an accumulation unit and a sampling unit interconnected in series The pressure, the outputs of which are connected to the corresponding inputs of the control unit, a temporary averaging unit, the inputs of which are connected respectively to the second output of the buffer memory unit and one of the outputs of the control unit, and the output is connected to the third input of the accumulation unit, a digital filtering unit connected between the corresponding output of the unit control and the third input of the display unit, the spectral analysis unit connected to the control output, the output of which is connected to the fourth input of the display unit, programmable the device, the output of which is connected to the second input of the digital filtering unit, the second input of the amplifier is connected to the output of the control unit, characterized in that it is equipped with a scan driver for displaying the vertical section of the controlled product in brightness form, connected by the control input to the control unit, and the output to the fourth input of the accumulation unit, a pre-processing unit connected to a separate output of the control unit and connected between the amplifier and the analog-to-digital converter, forms the inventor of the characteristics of the time sensitivity adjustment and the chart generator amplitude - distance - diameter, connected by the first inputs to the corresponding outputs of the control unit, the outputs - with the fifth and sixth inputs of the display unit, the second inputs - with the corresponding outputs of the programmable storage device, and the amplifier is made with a controlled time circuit gain control.  2. The digital ultrasonic flaw detector according to claim 1, characterized in that the pre-processing unit is made in the form of a filtering circuit, an envelope allocation circuit and a switch, designed to alternately connect these circuits to an amplifier and an analog-to-digital converter.

Images