SU1126863A1 - Eddy-current flaw dedector amplitude selection device - Google Patents

Abstract

A DEVICE AMPLITUDE SEPECCA OF THE VORTEX RELATED DEFECTOSCOPE containing a comparator, an amplitude detector, the input of which is connected to the measuring input of the comparator, and an inertial filter, characterized in that, in order to increase the reliability of the control, it is provided with a key connected between the input part of the incentive part, which will be in place of one of one of them, which will be used by the incentive unit, which will be connected to the inertial component that will be used by the inceptive component. at the same time The key input is connected to the comparator output, and a large-scale amplifier with an adjustable gain factor connected between the output of the inertial filter and control of the comparator input. (L

Description

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The invention relates to the monitoring of the control of materials and products, and can be used for the inspection of moving endless products, .S

The devices of amplitude selection of eddy current flaw detector s are known, which contain a detector that controls the level of the threshold of operation of the comparators.

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The disadvantage of such devices is that the level of the comparator triggering is set constant. or it is discretely changed by the operator, which does not allow one to withstand constant-S-signal-to-noise ratio when the level of Bguya changes, which reduces the reliability of the control.

Closest to the invention is an amplitude section of a eddy current lecture on a flap; containing a comparator, amaktkudny detector, the input of which is connected to the measuring input of the comparator, and an inertial monitor, its input 25 is connected to the output of the amplitude detector, and the output to the control input of the comparator L21.

When monitoring extended products, the output voltage of the inertial filter located after the detector is set to a voltage equal to a magnitude of interference. This stress is the threshold for the comparator. A useful signal that exceeds the level of 35 degrees and, consequently, exceeds the level of the comparator threshold, passes to the output of the comparator, which leads to the actuation of the actuator: mechanisms. the reliability of the control is reduced to 40 liters if the time of the subsequent pulses of the useful signal is less than the constant time of discharge of the inertial filter, since the useful signal raises the threshold of the comparator 45. torus to a value equal to the amplitude of the signal. In this case, the useful signal is involved in the formation of the threshold level of the trigger of the comparator. In addition, the signal-to-ratio ratio is practically equal to unity and there is no possibility to regulate it.

The purpose of the invention is to increase the reliability of the control.

This goal is achieved by the fact that 55 a device for amplitude selection of an eddy current flaw detector containing a comparator, an amplitude detector, whose input is connected to a measuring input of a comparator, and an inertial filter, is provided with a switch connected between the input of the inertial filter and the output of the amplitude detector, while the control input the key is connected to the output of the comparator f by a large-scale amplifier with an adjustable gain factor, connected between, the output of the inertial filter and the control input of the comparator.

In the drawing of the g; presented the structure of the proposed device.

The device contains a comparator 1 amplitude detector 2, the input of which is connected to the measuring input of the comparator, a key 3, the measuring input of which is connected to the output of the amplitude remote detector, and a control input to the output of the comparator 1, inertial filter 4 located on the output of the key, large-scale an amplifier 5 with a regulated gain, the input of which is connected to the output of the inertial filter, and the output to the control. to the comparator input.

The device works as follows.

If there is no: at the measuring input of the useful signal comparator, the output voltage of the amplitude detector 2 establishes a constant voltage close in magnitude to the active noise. On. The output of the inertial filter 4 is a constant voltage, in terms of practical value, the same as. and at the output of the amplitude detector 2, but it led: the pulsation is smaller. After amplification by the scale amplifier 5, this voltage is applied to the control; the AI input lco fflaperato and is threshold-1. In the case of a useful signal at the input of the comparator 1, exceeding the threshold voltage of the comparator 1, a pulse is formed with a duration equal to the time during which the amplitude of the signal exceeds the value of the selection threshold. In this case, the voltage at the output of the amplitude detector 2 begins to grow at the moment when the signal amplitude exceeds the noise level j, i.e. the value of the constant voltage, previously established on the output of the amplitude detector 2,

and increases to a value equal to the threshold voltage at the control input of the comparator 1. After the comparator T is triggered, as a result of the closure of the key 3, the voltage at the output. The amplitude detector begins to decrease. This process lasts as long as the signal at the comparator input exceeds the threshold voltage level, after which the voltage at the comparator output becomes zero, the key 3 opens, and the voltage at the detector output again rises to a certain value. The voltage at the output of the inertial filter is close in amplitude to the voltage at the output of amplitude detector 2, however, since the amplitude of the pulsations at the output of filter 4 is much less than at the output of amplitude detector 2, the voltage at the output of the optical fiber does not change when the amplitude detector is triggered 2. Since the voltage at the output of the inertial filter 4 is close to the amplitude of the interference, the gain of the scale amplifier is practically equal to the signal-to-noise ratio of the device. When the gain is changed, the signal-to-noise ratio automatically changes.

The construction of an amplitude selection device according to the proposed scheme makes it possible to increase the reliability of control by automatically setting the threshold level of the device depending on the interference level, while eliminating the impact of the useful signal that exceeds the comparator threshold level by the threshold value and the possibility of setting the required signal-to-noise ratio.

Claims (1)

DEVICE OF AMPLITUDE SELECTION OF A VORTEX RANGE DEFECTOSCOPE, containing a comparator, an amplitude detector, the input of which is connected to the measuring input of the comparator, and an inertial filter, characterized in that, in order to increase the reliability of control, it is equipped with a key connected between the input of the inertial filter and the output of the amplitude detector while the control input of the key is connected to the output of the comparator, and a large-scale amplifier with an adjustable gain connected between the output of the inertial filter and controlling th input of the comparator. ё О) 00 О G0>