JPS60230010A - Radiation thickness gauge - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement in a radiation thickness meter for measuring the cross-sectional shape of an object to be measured such as a steel plate.

[Technical background of the invention]

For example, in a rolling process, the cross-sectional shape (profile) of a copper plate as an object to be measured during rolling is measured. FIG. 1 is a configuration diagram of a conventional X-ray thickness meter for measuring the cross-sectional shape of an object to be measured. This X-ray thickness gage consists of a thickness detection section 1 and a signal processing device 2.
X-ray generators 4, 5.6 are arranged in the width direction of the object to be measured 7, and multi-channel X-ray detectors 8, 9° are mounted on the lower frame 3b facing the X-ray generators 4, 5.6, respectively. 10 are arranged. Therefore, the X-ray generators 4, 5.6 emit X-rays 4a in the width direction of the object 7 to be measured.

5a and 6a, respectively, and these X-rays 4a
, 5a, (3a is emitted so as to overlap with the adjacent X-ray. Then, multi-channel X-ray detectors 8, 9
．． 10, a plurality of, for example, 320 ionization chambers are connected to the object to be measured 7.
The configuration is such that they are arranged in the width direction. The ionization currents generated in these ionization chambers are converted into voltage signals for each channel, roughly A/D converted, and sent to the signal processing device 2 as thickness detection signals. Note that reference numerals 11, 12, and 13 are single substrates that are set at predetermined positions when calibrating the X-ray thickness gauge itself. In other words, this X-ray thickness gauge is
The thickness detection signal obtained when X-rays are transmitted through only the reference plates 11, 12, 13, and the thickness detection signal obtained when X-rays are transmitted through the object 7 with reference plates 11, 12, 13 removed. The thickness is calculated based on the difference between the measured thickness detection signal and the measured thickness detection signal.

Then, each multi-channel X-ray detector 8 of the thickness detection section 1
, 9.10, each thickness detection signal corresponding to the incident X-ray dose is sent to the plate thickness conversion section 14 of the signal processing device 2. This plate thickness converter 14 takes in thickness detection signals for each channel, and calculates the plate thickness for each channel based on the voltage values of these thickness detection signals. The obtained plate thickness data is sent to the display processing section 16 according to the command from the main control section 15.
The display processing section 16 calculates the cross-sectional shape of the object 7 based on the plate thickness data of each channel and the position of each ionization chamber. This cross-sectional shape is displayed as a pattern on the display section 17. Note that the main control unit 15 is connected to the signal processing device 2.
It also controls the set of reference plates 11, 12, and 13. Further, 18 is an X-ray generation control section.

[Problems with background technology]

The measurement accuracy of the above-mentioned X-ray thickness gauge is as follows: C-frame 3
It is determined by the installation accuracy with respect to the rolling line and the positional deviation of the object 7 to be measured. In other words, the plate thickness converting section 14 reduces the thickness by assuming that the object 7 to be measured is always traveling at a predetermined position.

Therefore, if the position of the object to be measured 7 changes, the accurate cross-sectional shape cannot be determined. However, since the actual object 7 to be measured is traveling at high speed, positional fluctuations, especially vertical fluctuations, are unavoidable.

However, with the conventional X-ray thickness meter, it was not possible to obtain an accurate cross-sectional shape 7.

[Purpose of the invention]

The present invention has been made based on the above-mentioned circumstances, and its purpose is to detect radiation that can accurately measure the cross-sectional shape of the object to be measured even if the position of the object to be measured fluctuates. Our goal is to provide thickness gauges.

[Summary of the invention]

The position of the object to be measured is changed at a predetermined position adjacent to the radiation generator and the multi-channel radiation detector, which are arranged opposite to each other so that the object is interposed between them. A variation detection means for detecting m is provided, and based on the amount of position variation of the object to be measured detected by the variation detection means, each amount of position variation of the part of the object to be measured corresponding to each channel of the multi-channel radiation detector is provided. The radiation thickness meter calculates the cross-sectional shape of the object to be measured based on the determined positional fluctuation amounts and the thickness detection signal output from the multi-channel radiation detector. .

[Embodiments of the invention]

Hereinafter, a case where the first embodiment of the radiation thickness meter according to the present invention is applied to an X-ray thickness meter will be described with reference to FIGS. 2 and 3. Note that the same parts as in FIG. 1 are given the same reference numerals, and detailed explanation thereof will be omitted. FIG. 1 is a configuration diagram of the XIm thickness gauge of the present invention. The lower frame 3b of this XwA thickness gauge has a position detector 2 as a variation detection means.
0.21.22 is provided. These position detectors 2
0, 21, and 22 detect the amount of vertical fluctuation of the object to be measured 7, and for example, a magnetic sensor is used. The position detectors 20, 21, and 22 are arranged in such a manner that each X-ray generator 4.5.6 and each multi-channel X-ray detector 8 are close to the multi-channel X-ray detectors 8, 9, and 10, respectively. .9.
Each multichannel X-ray detector 8 on a line connecting the center of 10
．． 9.10 is located at a position that intersects with the horizontal plane passing through the ionization chamber located in the center of 9.10.

On the other hand, the position processing device 3 is provided with a variable position conversion section 30 as a variation amount n section. This variable position transformation ti
J30 corresponds to each channel of each multi-channel X-ray detector 8, 9.10 for each multi-channel X-ray detector 8, 9.10 by the variation detection signal from each position detector 20, 21.22. 1. It calculates the amount of positional variation of the part of the object to be measured. A specific calculation of the amount of positional variation will be explained with reference to FIG. 3 for the X-ray generator 4 and the multi-channel X-ray detector 8. Note that the same applies to the other X-ray generators 5.6 and multi-channel X-ray detectors 9 and 10, so the description thereof will be omitted. In Figure 3, x
#1 generator 4 and position detector 20 are shown as central points, and object 7 is shown schematically by lines. Here, the center position of the multi-channel X-ray detector 8 with respect to the object to be measured 7 is known, and the distance 1ir between the X-ray generator 4 and the multi-channel X-ray detector 8 is also known in advance. Therefore, the variable position converter 30 converts the multi-channel X-ray detector 8
, that is, the transmission position X in the object 7 of the X-ray detected by the n-th ionization chamber 8n from the ionization chamber at the position where the position detector 20 is installed. Here, if the size of the X-ray entrance window of the ionization chamber 8n is 42 and the distance from the center position of the multi-channel X-ray detector 8 to the ionization chamber 8n is 2, then A(-(1...(1) and , 奢-n θ=□ ...+21 γ, x=P-tan θ = (,r-D)tan θ (3) Therefore, the variable position converter 3 degrees From the variation mD detected by .22, the variation in the position X of the part of the object to be measured 7 corresponding to each ionization chamber of each multi-channel X-ray detector 8 is determined by equation (3).

The display processing unit 31 displays each variable position X determined by the variable position converting unit 30 and the multi-channel X-ray detector 8.9.10.
The cross-sectional shape of the object to be measured 7 is determined based on the thickness data obtained from the respective thickness detection signals outputted from the r'. Note that 14 is a plate thickness conversion section, 15 is a main control section, and 18 is an X-ray generation control section.

Next, the operation of the XIa thickness gauge configured as described above will be explained. Xm4a, 5a from each X-ray generator 4,5.6 under the control of the X-ray generation control section 18.

When the X-rays 6a are emitted, these X-rays 4a, 5a, and 6a pass through the object to be measured 7, and each multi-channel XWA causes a current to flow in each ionization chamber according to the amount of incident X-rays. . These electric lights! The current is converted into a voltage signal, further A/D converted, and sent to the plate thickness conversion section 14 as a thickness detection signal.
sent to.

By the way, since the object to be measured 7 is traveling at high speed, the position of the object to be measured 7 is fluctuating up and down.

This vertically fluctuating position is detected by each position detector 20, 21°22. That is, each position detector 20.21.2
2 generates magnetism, and the fluctuation ID shown in FIG. 3 is detected by this magnetic change.

The fluctuations detected by the position detectors 20, 21, and 22 are then sent to the fluctuation position converter 30 as fluctuation amount detection signals. The variable position converter 30 takes in each variable detection signal output from each position detector 20, 21.22, and converts each multi-channel X-ray detector 8 to each multi-channel X-ray detector 8, 9, 10 separately. .9.10 The changed position of the portion X of the object to be measured 7 corresponding to each ionization chamber is determined by calculating the above equation (3). And, in the customer's calligraphy ranking y L', Ijingumi Uguri Q 11. j! On the other hand, the plate thickness conversion section 14 includes each multi-channel X-ray detector 8, 9.
．． The thickness detection signals outputted from the respective multi-channel X-ray detectors 8, 9, .
Calculate the thickness of the portion corresponding to each of the 10 ionization chambers. The thickness of the portion corresponding to each of the ionization chambers thus determined is transferred as thickness data to the display processing section 31 according to a command from the main control section 14. Note that the transfer of the thickness data to the display processing section 31 and the sending of each variable position X determined by the variable position converting section 30 to the signal processing section 31 are synchronized. The portion of the object to be measured 7 detected by each ionization chamber of the detector 8.9.10 and each position detector 20, 21.2
The variable positions x of the object to be measured 7 obtained by the detection in step 2 are made to coincide with each other.

Then, the display processing section 31 uses the variable position X for each channel of each multi-channel X-ray detector sent from the variable position converting section 30 and the plate thickness data transferred from the plate thickness converting section 14. The cross-sectional shape of the object to be measured 7 is calculated. The obtained cross-sectional shape is patterned and displayed on the display area, for example C.
It is displayed on the R7 display device 17.

In this way, in the X-ray thickness meter of the present invention, the position detector 20 is located at the center of each multi-channel X-ray detector 8.9.10 close to each multi-channel X-ray detector 8.9.10. .21, 22 are arranged, and these position detectors 20.
According to the vertical fluctuation ID detected by 21.22, the fluctuation position converter 30 converts each multi-channel X-ray detector 8.9.1
The variable position X of the portion of the object 7 corresponding to each channel of 0 is determined, and the cross-sectional shape of the object 7 is determined based on the determined variable position X and the thickness detection signal. Even if the position of the object to be measured 7 fluctuates up and down, the position of the object to be measured 7 corresponding to each ionization of each multi-channel X-ray detector 8.9.10 is corrected according to the amount of fluctuation, and Cross section of object 7 □The shape of the surface can be seen. Therefore, the cross-sectional shape of the object to be measured 7 can be determined accurately even if it fluctuates up and down.

Next, a second embodiment of the X-ray thickness meter of the present invention will be described with reference to FIGS. 4 and 5. Note that the same parts as in FIG. 2 are given the same reference numerals, and detailed explanation thereof will be omitted.

FIG. 4 is a configuration diagram of the X-ray thickness meter of the present invention. The variation detection means of this X-ray thickness gauge consists of each position detector 2 shown in FIG.
In addition to 0.21.22, there are position detectors 20.2 at both ends of each multi-channel X-ray detector 8,9°10.
1°22 and the same position detectors 20a, 20b, 21a.

21b, 22a, and 22b are arranged.

On the other hand, the variable position converter 40 of the signal 9a processing device 3 converts the position detectors 20, 20a, 20b, -22, 22a, 22
Each multi-channel X-ray detector 8, 9 captures each variation detection signal outputted from b, and detects when the measured object 7 fluctuates vertically and tilts due to these captured variation detection signals.
．． It has a function of measuring the positional fluctuation of the part of the object to be measured 7 corresponding to each of the 10 channels. Specifically, FIG. 5 is a schematic diagram. Therefore, a case will be described in which the object to be measured 7 is tilted to the right. Here, DO−Db=
If ΔD is used, the diagonal Φ1 on the right side is intersected. As a result, the variable position Xa becomes. Here 02=AI2・
It is n/r.

Furthermore, when the object to be measured 7 is tilted to the left by Φ2 (not shown), the following equation is obtained, which is the same as when the object 7 is tilted to the right. Note that θ=Affi·n/r. Therefore, the position detectors 20a, 21a and 22a each detect the fluctuation 108, and the position detectors 20b and 21h detect the deviation Db.

On the other hand, if the object to be measured 7 is tilted, each thickness detection signal must be corrected according to the degree of the tilt. In other words, this thickness gage uses the thickness detection signal obtained when X-rays are transmitted through the reference plate 11, 12, 13 corresponding to the thickness of the object 7 to be measured as a reference. The thickness is determined by determining the thickness detection signal obtained when the film is transmitted through the film. Therefore, as shown in FIG.
When the slope becomes like 7a, X
The width that the line passes through differs.

Therefore, the amount of correction when the treasure 7 to be measured is tilted is calculated as follows. Here, the thickness of the object 7 shown in FIG. 6 is T, the width through which X-rays are transmitted when the object 7 is not tilted is T1, and the width through which X-rays are transmitted when the object 7 is tilted by Φa. 1 where the width is T2 and・T1・COSθ=T ・・・・・・(8)T2−cos
'(θ+Φa＞=T ・------(9) From these 8th and 9th equations, TI ・cos θ=T2cos(θ+Φa)...
... (10) becomes. In other words, each thickness detection signal is COSθ, /C0
It will be multiplied by 5 (θ+Φa). Note that Φa indicates position detectors 20a, 20b, 21a, and 21b.

This can be determined from the fluctuation amount detection signals output from 22a and 22b. Then, correction of this thickness detection signal is performed, for example, in the plate thickness conversion section 14.

Therefore, the display processing unit 41 displays the amount of variation [X
The cross-sectional shape of the object to be measured 7 is determined by a and the thickness data corrected by the correction amount (cos θ/cos (θ+Φa)).

In the X-ray thickness meter configured in this way, it is possible to obtain an accurate cross-sectional shape of the object to be measured 7 even if the object to be measured 7 moves up and down, and in addition, each multi-channel
Position detectors 2 are installed at both ends of the line detectors 8, 9, and 10, respectively.
0a, 20b, 21a, 21b.

22a and 22b are arranged so that correction can be made even when the object to be measured 7 is tilted, so even if the object to be measured 7 is tilted, the accurate cross-sectional shape of the object to be measured 7 can be determined.

Note that the present invention is not limited to the first and second embodiments described above. In the first and second embodiments described above, the case where the thickness meter is applied to an X-ray thickness meter has been described, but it can also be applied to a radiation thickness meter that uses β-rays or γ-rays depending on the object to be measured 7, not just XII. It's okay.

[Effects of the Invention] According to the present invention, a variation detection means for detecting the amount of position variation of the object to be measured is provided adjacent to the multi-channel radiation detector,
Based on the amount of positional variation detected by this variation detection means, the variation calculating section calculates the amount of positional variation of the part of the object to be measured corresponding to each channel of the multi-channel radiation detector, and uses this amount of positional variation and thickness data to determine the cross-sectional shape. Therefore, even if the position of the object to be measured changes, it is possible to provide a radiation thickness meter that can detect this change and accurately measure the cross-sectional shape of the object to be measured.

[Brief Description of the Drawings] Fig. 1 is a configuration diagram of a conventional X-ray thickness meter, and Fig. 2 is a case in which the first embodiment of the radiation thickness meter according to the present invention is applied to an X-ray thickness meter. FIG. 3 is a schematic diagram for explaining the action of the variable position converter in the X-ray thickness meter shown in FIG. 2, and FIG. 4 is a second implementation of the radiation thickness meter according to the present invention. A configuration diagram when the example is applied to an X-ray thickness meter, FIG. 5 is a schematic diagram for explaining the action of the variable position converter in the X-ray thickness meter shown in FIG. Schematic 3...C for explaining the correction of the thickness detection signal of the XII thickness gauge shown in the figure.
Frame, 4.5.6... X-ray generator, 7... Measured object, 8.9.10... Multi-channel X-ray detector, 1
4... Plate thickness conversion section, 15... Main control section, 17...
Display unit, 18... X-ray generation control unit, 20, 21° 22
. . . position detector, 30 . . . variable position conversion unit, 31.
...Display processing section. Figure 4 82LJ Figure 6

Claims (3)

[Claims] (1) In a radiation thickness meter that measures the cross-sectional shape of an object to be measured, a radiation generator that emits radiation in the width direction of the object to be measured and a multi-layer a channel radiation detector; provided at a predetermined position adjacent to the multichannel radiation detector;
fluctuation detection means for detecting the amount of positional fluctuation of the object to be measured;
a variation calculation unit which calculates each positional variation amount of the part of the measured object corresponding to each channel of the multi-channel radiation detector based on the positional variation amount of the measured object detected by the variation detection means; A cross-section calculation section that calculates the cross-sectional shape of the object to be measured based on the amount of positional variation determined by the variation calculation section and the thickness detection signal output from the multi-channel radiation detector. Radiation thickness gauge. (2) The fluctuation detection means detects vertical fluctuations of the object to be measured by installing a fluctuation detector on a line connecting the radiation generator and the center of the multi-channel radiation detector. Radiation thickness gauge described in ). (3) The variation detection means includes a variation detector installed on a line connecting the radiation generator and the center of the multi-channel radiation detector, and variation detectors arranged at both ends of the multi-channel radiation detector. and detecting vertical fluctuations and tilt fluctuations of the object to be measured.
The radiation thickness meter described in section 1).