SU1078316A1 - Ultrasonic flaw detector - Google Patents

Abstract

ULTRASONIC DEFEKTOSKOP, containing serially connected synchronizer, exciter of ultrasonic oscillations and ultrasonic transducer, serially connected strobe pulse generator and amplifier connected between the synchronizer and the output of the ultrasonic transducer, connected in series the first comparator and trigger, the second input of which is connected by a synchronizer and synchronizer of the ultrasonic transducer, which are connected in series by the first comparator and trigger, the second input of which is connected by a synchronizer and synchronizer of the ultrasonic transducer, which are connected in series by the first comparator and the trigger, the second input of which is connected to the synchronizer and synchronizer of the ultrasonic transducer. characterized in that, in order to increase the reliability of the control, it is provided with usi connected between the output the indicator and the input of the indicator are connected in series by voltage dividers, a multiplexer connected to the input of the first comparator, a second comparator and a counter whose output is connected to the U control input of the multiplexer (The second input of the counter is connected to the trigger output and the third to the synchronizer.

Description

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L of 1; benting refers to the inaccessible ultrasound testing and can be used in the defectology of flat and complex enclosures to determine the equivalent area of defects. A known ultrasonic pulse flaw detector containing a synchronous jam, a causative agent of ultrasonic vibrations, an ultrasonic transducer, an amplifier, an attenuator, an electron-beam indicator, a sweep generator Cl. The disadvantage of a flaw detector is a low monitoring performance. The closest to the invention is an ultrasonic flaw detector containing a serially connected synchronizer, an ultrasonic transducer and an ultrasound transducer, serially connected strobe pulse generator and an amplifier connected between the synchronizer and the output of the ultrasonic transducer, the first comparator connected in series and the trigger, the second input of which is connected with synchronizer, and indication | Thor t2. A disadvantage of the known device is the low reliability of the control. This is due to the fact that the conversion of an analog signal to a discrete one and vice versa for influencing the regulating element of the amplifier leads to additional errors in measuring the amplitude of the signal from the defect. The purpose of the invention is to increase the reliability of the control. The goal is achieved by the fact that an ultrasonic flaw detector containing a synchronously connected synchronizer, a driver of ultrasonic vibrations and an ultrasonic transducer, connected in series to a strobe pulse former and an amplifier connected to the synchronizer and output of the ultrasonic transducer, connected in series to the first comparator and a trigger, the second input of which is connected to the synchronizer and an indicator provided with an amplifier connected between the output of the amplifier and the input. sequently connected dividers voltage multiplexer connected to the input of the first comparator, a second comparator and a counter, whose output is connected to a control input of the multiplexer, a second input connected to the output of the counter trigger, and the third with the synchronizer. The drawing shows the block diagram of the ultrasonic flaw detector. Ultrasonic flaw detector contains synchronizer 1 connected in series, ultrasonic oscillation exciter 2 and ultrasound transducer 3, serially connected strobe pulse shaper 4 and amplifier 5 connected between synchronizer 1 and output of ultrasonic transducer 3, serially connected first comparator 6 and trigger 7, the second input of which connected to the synchronizer 1, and the indicator 8 connected between the output of the amplifier 5 and the input of the indicator 8 serially connected dividers 9 n multiplexer 10 connected to the input of the first comparator 6, the second comparator 11 and the counter 12, the output of which is connected to the control input of the multiplexer 10, the second input of the counter 12 is connected to the output of the trigger 7, and the third is working with the synchronizer 1. The ultrasonic flaw detector works in the following way. The pulses of synchronizer 1 accelerate trigger 7 to state 1, enter the counting input of counter 12, and start the gate 4 shaper and ultrasonic oscillation pathogen 2, the excitation voltage of which goes to ultrasonic transducer 3. The latter emits and receives ultrasonic vibrations. The amplitude of reflected and received ultrasonic vibrations carries information about the dimensions of the reflecting defects. The received signal is fed to the input of the amplifier 5, controlled by the strobe-pulse of the strobe-pulse shaper 4. The gain of the amplifier 5 is controlled by a strobe pulse in such a way that during its presence at the control input of the amplifier 5 its transfer coefficient is equal to the nominal value, and at the time of the absence of a strobe pulse, the transfer coefficient is equal to ZERO. The amplified signal passes to the input of dividers 9 voltage, the number of which is equal to the number of steps of the variable transmission coefficient. The outputs of the voltage dividers 9 are connected to the corresponding linear inputs of the multiplexer 10 in such a way that, when sequentially switching the multiplexer 10, the transmission coefficient of the signal transmission path from the defect changes by the value of fp, where n is the number of synchronizer 1 pulses received at the counting input of the counter 12, 4 - discreteness of the transfer factor of the voltage divider 9, dB. Suppose that with the next pulse of the synchronizer 1, the counter 12 is set to the zero initial state. In this case, the code of the number recorded in the cells of the counter 12 is fed to the input of the indicator 8 and the control input of the Multiplexer 10. The latter connects to its output the line input of voltage dividers 9. Next, the signal arrives at the inputs of the first and second comparators 6 and 11. The first comparator 6 has a response threshold less than the response threshold of the second comparator 11, and the difference between the thresholds (f- (dB), in order to ensure the operability of the ultrasonic flaw detector) If, before the arrival of the next pulse of the synchronizer 1, the signal level does not reach the trigger threshold of the first comparator 6, then the trigger 7 remains in state 1. The output from the trigger output 7 goes to the Stop input of the counter 12 for which 1 is ogicheska by allowing a signal. Thus. The next pulse synchronizer 1 switches the counter 12. The latter in turn influences g to a control input of multiplexer 10, inside of which is connected to the output line input connected to the divider 9 voltage.

In such a mode of sequential switching of voltage dividers 9, the ultrasonic flaw detector operates until the signal amplitude level at the input of the first comparator 6 reaches the response threshold. From the output of the first comparator 6, the control signal at the input R sets the trigger 7 to the state O. The presence of a logical O at the input of the stop of the counter 12 prohibits the counting of synchronizer 1 pulses. If the a1 phase of the defect signal does not change, then in each clock of the synchronizer

1 trigger 7 is reset

state, and counter 12 does not change the states of its trigger cells. The constant state of the counter 12 is indicated by the indicator 8, indicating that the defect signal level is above the set sensitivity level of the ultrasonic flaw detector. Thus, indicator 8 is directly in the process.

5 of the ultrasonic flaw detector indicates the value of the conditional coefficient of detection K.

If the amplitude of the defect signal has decreased, then reset trigger 7 in

0, state O does not occur, and counter 12 counts synchronizer pulses 1 until the first comparator 6 triggers again. If the amplitude of the defect signal increased and reached the second comparator threshold 11, then -. The last one is triggered and the output signal will set the counter 12 at the input R to the zero initial state. Next, the ultrasonic flaw detector works according to the described cycle.

The use of an ultrasonic flaw detector makes it possible to increase the reliability of the control in determining the area of defects using S KN diagrams, since additional errors associated with double signal conversion are eliminated.

Claims (1)

ULTRASONIC DEFECTOSCOPE, comprising a synchronizer, an ultrasonic vibrator and an ultrasonic transducer connected in series, a strobe pulse former and an amplifier connected in series between the synchronizer and the output of the ultrasonic transducer, a first comparator and a trigger connected in series, the second input of which is connected to the synchronizer, and an indicator characterized in that, in order to increase the reliability of the control, it is equipped with amplifiers connected between the output For the indicator input and the voltage dividers connected in series, a multiplexer connected to the input of the first comparator, a second comparator and a counter whose output is connected to the control input of the multiplexer, the second counter input is connected to the trigger output, and the third to the synchronizer.