SU1315879A1 - Device for determining longitudinal dimensions of flaws on radiographic pictures of long-distance pipeline welds - Google Patents

Abstract

The invention can be used in radiographic monitoring to determine the radial dimensions of defects in radiographic images of welded joints of main pipelines. The goal is to increase the accuracy of determining the radial dimensions of weld defects. The basis of the device based on the reference photometry - -. A method for measuring the density of a blackened radiograph of a welded joint. When measuring, the light source 1 together with the photo sensor 2 of the measuring channel is transferred to the seam zone using the transverse scanning mechanism 3, the signal from the enable input of the memory 12 is removed and the recorded signal is stored in memory all the time until the end of measurement of this film. When transversely scanning, in order to maintain the same incident light fluxes on the film, an optical wedge 5 is provided in the measuring and reference channels, the light tray at the output of which varies quadratically due to the distance from the light source 1 to the mirror 4. The entire device has an electronic control circuit. 1 il. with S (L OO O1 00

Description

113

The invention relates to optical instrumentation and can be used in radiographic monitoring to determine the radius of the size of defects in radiographic images of the welds of main pipelines.

The purpose of the invention is to improve the accuracy of determining the radial dimensions. defects of welds.,

The drawing shows the functional diagram of the device.

The device contains source 1

The light and the photo sensor 2 of the measuring channel are rigidly connected and mounted on the transverse scanning mechanism 3, mirror 4, the optical wedge 5 and the photo sensor 6 of the reference channel mounted on the longitudinal scanning mechanism, the sensor 7 for positioning the reference, the longitudinal scanning mechanism 8, are kinematically connected Logged with the transverse scanning mechanism 3, logarithmic amplifiers 9 and 10 of the measuring and reference channels, whose inputs are connected to the photosensors 2 and 6 of the measuring and reference channels, respectively, and the outputs the corresponding inputs of the differential amplifier 11, the output of which is connected to the input of the storage device 12, to the permitting input of which the sensor 7 is connected to the reference, and the output is connected to the first input of the dividing device 13, to the second input of which the master 14 of the standard height code is connected, multiplication device 15 the input of which is connected to the output of dividing device 13, and the second input to the output of differential amplifier 11, indicator 16 connected to the output of device I5 of the multiplier, and moving mechanism 17 iograficheskogo image (film).

The instrument is based on a reference photometric method for measuring the density of a blackened X-ray image of a welded joint. The blackening density of the image is measured relative to the density of the pipe wall. The blackening density of the D radiograph (film) is determined by the formula

 -.

Where

1e and TI, respectively, falling on the film and transmitted through it light streams.

   Y; MA About TR-OST

At

tr

- JT

/ Sd

9T

D

tr

where is the transmitted light flux

through the walls of the pipeline;

- transmitted luminous flux through the wall thickness of the pipeline plus the height of the standard;

-the change in density corresponding to an increase in pipe wall thickness by the value of the standard height;

-the density of the blackening of the image corresponding to a certain thickness of the pipe wall;

-the density of the blackening of the image corresponding to the wall thickness plus the height h of the standard.

-Tf- - coefficient

dUjT

characterizing the change in pipe wall thickness per unit of optical density, is constant for this image.

Then the gain value of the welded

D

ET

At the same time, K

suture can be defined as follows

h;, K (DT.p-D,) KdD, where D; f is the density of the blackening of the seam; AD; f is the change in the density of the blackening of the image at the weld joint relative to the density of the blackening of the image of the pipe.

Light source 1 creates two directional light beams. One light beam through the optical wedge 5 and the X-ray image falls on the photosensor 2 of the measuring channel, and the second - on the mirror 4 - and reflected from it through the X-ray image to the photosensor 6 of the reference channel. At the same time, at the output of photosensors, signals appear that are proportional to the luminous flux passed through the image. The magnitude of the transmitted light flux depends on the density of the blackening of the image. With the same density of the blackening of the image, the outputs of the photosensors 2 and 6 show the same size signals, which are amplified by logarithmic amplifiers 9 and 10 2

. 313

served on the corresponding inputs of the differential amplifier 11. At the output of the differential amplifier 11, the difference signal corresponding to the same blackening density of the picture is equal to zero. From the output of the differential amplifier 11, the difference signal is fed to the memory 12 and to the multiplication device 15. In this case, the multiplication device 15 gives the signal code equal to zero, and the indicator reading 16 is also equal to zero.

The photosensor 6 of the reference channel is always in the zone, the density of the blackening of the image of which depends only on the wall thickness of the pipeline, and is moved by means of the mechanism 8 for the longitudinal scanning along the seam in the image together with the mechanism 3 for the transverse scanning. Using the transverse-scanning mechanism 3, the light source 1 together with the photosensor 2 of the measuring channel is moved into the zone of the reference location so that the position of the reference falls on the optical axis of the light source of the photometric of the measuring channel. I

In this case, the standard location sensor 7 triggers, which gives a signal to the enable input of the storage device 12, and a differential signal appears at the output of the differential amplifier 11, corresponding to the change in the blackening density of the image, determined by the height of the standard. This difference signal is recorded in a memory device 12, from the output of which is fed to one input of the dividing device 13, to the second input of which a signal is received from setpoint 4 of the standard height code. As a result, the input signal of the multiplication device receives a signal corresponding to the expression. At the output of the multiplication device 15, there will be a signal equal to Tb, i.e. indicator 16 shows the true value of the height of the standard.

When measuring, the light source 1 together with the photo sensor 2 of the measuring channel with the help of the transverse scanning mechanism 3 transfers from to the seam zone, the signal from the enable input of the memory 12 is removed and the recorded signal is stored in memory all the time

58794

before the end of measurement of this film. Thus, scanning and determination by indicator 16 bg is performed.

parameters

 LO

Dv

at

When transversely scanning, an optical wedge 5 is provided in order to maintain the same incident light fluxes on the film in the measuring and reference channels, the light flux at the output of which varies quadratically due to the distance from the light source 1 to the mirror 4.

The invention allows to improve the quality control of welded joints, the reliability and reliability of control of trunk pipelines during construction.

Form m a la invention

A device for determining the radial dimensions of defects in radiographic images of the welds of main pipelines, containing an optically coupled light source and a photo sensor with a logarithmic measuring channel amplifier and a photo sensor

with a logarithmic reference channel amplifier, a differential amplifier, whose inputs are connected to the outputs of logarithmic amplifiers, a mechanism for moving a radiographic image of the weld, a mirror, an optical wedge and an indicator, characterized in that, in order to improve the accuracy of determining the radial dimensions of weld defects,

it is equipped with a cross-scanning mechanism, a longitudinal scanning mechanism, a standard position sensor, a storage device, a set of a standard height code, a dividing device and a multiplication device, while the light source and the photo sensor of the measuring channel are mounted on the cross-scanning mechanism, mirror, photo sensor

the reference channel and the optical wedge, mounted on a longitudinal scanning mechanism, which is kinematically associated with a cross-scanning mechanism, the mirror is located on

the optical axis, the light source is the photo sensor of the reference channel, and the optical wedge is on the optical axis the light source is the photo sensor of the measuring channel, the output of the differential sensor is 1313158796

The phone is connected to the input of the memory; which is connected to the setting device of the output device code, to the enabling input of the reference pattern, and the output is connected to;

which the location sensor is connected to the first input of the multiplying device,

the standard, and the output, which stores the second input, is connected to the device, is connected to the first input of the differential amplifier, and

the dividing device, to the second input and output connected to the indicator.

Claims (1)

Claim A device for determining the beam dimensions of defects in radiographic images of welds of main pipelines, containing optically coupled light source and a photo sensor with a logarithmic amplifier of the measuring channel and a photo sensor with a logarithmic amplifier of the reference channel, a differential amplifier whose inputs are connected to the outputs of the logarithmic amplifiers, a mechanism for moving the radiographic image of the welded a seam, a mirror, an optical wedge and an indicator, characterized in that, in order to increase the accuracy of the detection In order to measure the radial dimensions of weld defects, it is equipped with a transverse scanning mechanism, a longitudinal scanning mechanism, a standard position sensor, a storage device, a standard height code adjuster, a division device and a multiplication device, while the light source and the measuring channel photosensor are mounted on the transverse scanning mechanism, a mirror , a reference channel photosensor and an optical wedge are mounted on a longitudinal scanning mechanism, which is kinematically connected transversely with the mechanism about scanning, the mirror is located on the optical axis, the light source is the photosensor of the reference channel, and the optical wedge is located on the optical axis, the light source is the photosensor of the measuring channel, the output of the differential amplifier 5 1315879 is connected to the input of the storage device, to the resolution input of which the location sensor of the reference is connected, and the output of the storage device is connected to the first input of the division device, the second input of which is connected to the master of the height code of the standard, and the output is connected to the first input of the device, multiplying Nia, the second input of which is connected to you go · 5 of the differential amplifier, and an output connected to the indicator.