JPS6024407A - Radiation thickness gage - Google Patents

Abstract

PURPOSE:To make it possible to continue the measurement of a shape even through any channel system fails, by dividing a detecting part of radiation, which is transmitted through a material to be measured, into a plurality of channel systems, removing the channel system, which outputs an abnormal signal, and performing an interpolation processing. CONSTITUTION:Radiation is projected from a rediation source in a radial shape so as to cover a material to be measured in the direction of lateral width. The radiation is transmitted through the material to be measured and converted into electric signals, which are attenuated in proportion to the thicknesses of the material to be measured by detecting elements 21-1-21-N for individual channel. The outputs of preamplifiers 22-1, 22-2... for the odd-number channels and the even-number channels are inputted to multiplexers 23A and 23B respectively, and supplied to plate-thickness converters 25A and 25B through A-D converters 24A and 24B. A data processing part 26 receivers the signals of the converters 25A and 25B, and computes the signals based on the selecting signal from an input selecting circuit 28. Thus the shape is measured. The output of the channel system, which sends out the abnormal detected signal, is removed and interpolation processing is performed by using the detected signals from the other channel systems. Thus the measurement can be continued.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to improvements in radiation thickness needles for measuring cross-sectional shapes of strips and the like.

[Technical background of the invention and its problems]

This type of radiation thickness meter has a radiation source 2 and a number of detection elements arranged in a line at both ends of a C frame I that is movably installed at a location A in a relatively bad environment, as shown in Figure 1. A multi-channel detector 3 is placed facing each other, and an object to be measured 4 is placed between the radiation source 2 and the multi-channel detector 3. Then, the radiation 5 irradiated from the radiation source 2 so as to cover the entire object to be measured 4 is transmitted through the object to be measured 4 and detected by the multi-channel detector 3,
After the output of this detector 3 is amplified by a noring ring 6° connected to each detection element, the multiplexer 7 sequentially switches channels to selectively output the amplifier output, and then the A-D converter circuit 8. A plate thickness converter 9 is converted into a digital signal and installed in a safe place 8.
sent to. This plate thickness converter 9 collects the plate thickness signal for each channel and then sends it to the data processing section 1o. here,
The plate thickness signal to each channel is converted into a profile R-turn of the object to be measured 4 and displayed on the subsequent CRT display section 11.

By the way, in the radiation thickness meter as described above, if an accident occurs in one of the multiplexer 7, A-D converter circuit 8, plate thickness converter 9, etc., the thickness cannot be measured and the object to be measured 4 is damaged. It becomes impossible to measure the shape of In this case, it is conceivable to perform repair work immediately, but there is a problem that the thickness measurement has to be temporarily stopped during this time, and if the plant is temporarily stopped while the object to be measured 4 is being transported online, it will cause a large amount of trouble. In many cases, it is practically impossible to cancel because of the damage that would be incurred.

In addition, the radiation thickness meter is divided into a detection part and a measurement part, but for ease of data transmission etc., the detection part installed in location A, which is in a bad environment, is equipped with a preamplifier f6 and a multiplexer 7.
However, there are disadvantages in that repair work requires a long time due to the presence of an A-D conversion circuit and the need to remove the effects of adverse environments.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and is a radiation thickness meter that can continue measurement even if an abnormality occurs in any channel system, and that has excellent reproducibility of the shape of the object to be measured based on the measurement results. Our goal is to provide the following.

[Summary of the invention]

According to the present invention, among the elements connected to the output side of a plurality of channel detectors, at least the detection section installed in a relatively bad environment or in a remote location is divided into, for example, an odd channel system and an even channel system. , for example, is a radiation thickness meter that uses an even channel system to detect radiation passing through the object even if a failure occurs in one of the odd channels, and performs shape measurement by calculation.

[Embodiments of the invention]

Next, an embodiment of the present invention will be described with reference to FIG. In the same figure, 21 is a multi-channel detector, which is not shown, but for example, as shown in FIG.
It is provided at one end of the frame to face the radiation source.

This multi-channel detector 21 has a configuration in which the number of detection elements 21-1 to 21-N equal to the number of channels are arranged in a line. The following description will be made by specifying the detecting element 21-1 for the second channel, the detecting element 21-2- for the second channel, and the detecting element 21-N for the N-th channel. Preamplifiers 22-1 to 22-N are connected to the output sides of the detection elements 21-1 to 21-N for each channel, respectively. and,
Among these preamplifiers 22-1 to 22-N, odd channel preamplifiers 22-1, 22-3. ... are connected to each fixed terminal of the first multiplexer 23A in a predetermined order, while the even channel preamplifiers 22-2, 22-4, . ... are connected to each fixed terminal of the second multiplexer 23B in the same (predetermined order). In other words, in this embodiment, multiple channels are
It is divided into two systems: odd number channels and even number channels. The selection terminal 23m of the first multiplexer 23A is connected to an A-D conversion circuit 24A and a plate thickness converter 25A.
is connected to the first input terminal 27a of the data processing unit 26 via the selection terminal 23 of the second multiplexer 23B.
b is the same <A-D conversion circuit 24B and plate thickness converter, 9
5B to the second input terminal 27b of the data processing section 26.

The detection unit is a multi-channel detector:) Z,,
fian f2z-x~22-N, multiplexer 23A
, 23B and the A-D conversion circuit 24A.

24F3, etc., but the plate thickness converter 25A.

25B and installed in a relatively bad environment or in a remote location A, a thickness converter 251.25 is installed as shown in Figure 2.
Divide into two systems up to B.

The data processing section 26 is installed in a good environment or in a central monitoring room B, and is connected to the input terminal selection circuit 2.
Based on the selection signals ajb, a, b of 8, the input end 27m,
27b or only the input end 27m, or the input end,
? 7b is selected and the plate thickness signal is taken in, data processing is performed according to the flowchart shown in FIG. 3, and the plate thickness distribution, that is, the profile/arm turn is created. The data processed by this data processing unit 26 is, for example, C
It is displayed on a display unit 29 such as RT. The input terminal selection circuit 28 may be switched manually based on the display result of the display section 29, or may be automatically switched using a known checking means built in the data processing section 26. It is assumed that the switching selection terminal 28m is grounded, for example.

Next, the operation of the radiation thickness meter as described above will be explained. For example, after installing the C-frame as shown in Figure 1, if radiation is radiated radially from the radiation source to cover the object to be measured in the width direction, this radiation will pass through the object and be detected by each channel. Radiation incident on the elements 21-1 to 21-N and with an attenuation degree proportional to the thickness of the object to be measured is transmitted to the detection elements 21-1 to 21 for each channel.
-N is converted into an electrical signal. The electrical signals converted by these channel detection elements 21-1 to 21-N are sent to corresponding Noriamps 22-1 to 22-N, respectively.
The amplified output of the odd channel serial 76; tz-1, ;t; t-s, . . . is sent to the first multiplexer 23A side, and the even channel preamp The amplified outputs of 22-2, 22-4°, . . . are sent to the second multiplexer 23B. The first and second multiplexers 231 and 23B receive the amplified output selected for each channel and send it to the A-D conversion circuits 24A and 24B, thereby converting it into a digital signal and converting the board thickness. 25k and 25B. The plate thickness converters 25A and 25B obtain plate thickness signals through predetermined signal conversion and send them to the data processing section 26 via first and second input ends 27m and 27b, respectively. In the data processing section 26, the odd and even channel thickness signals a 1 + a 2 *... and bl, b2 .・・・
・ are sequentially fetched and stored in the memory, and the selection signal of the input terminal selection circuit 28 is fetched to select which input terminal 27m,
21b is selected, and if the input terminals 27m and 21b are selected by the i+b selection signal, the odd channel thickness signals a 1 , *2° . . . and the even channel thickness signals b1 . b2... and a1+b1
112+b2 . . . are calculated, the profile pattern of the object to be measured is converted, and the cross-sectional shape of the object to be measured is displayed on the display unit 29.

If a failure occurs in one channel of the even-numbered channel system, and the display on the display unit 29 or the data processing unit 26 determines that the failure has occurred, the selection terminal 28a of the input terminal selection circuit 28 is Alternatively, since the a selection signal to automatically select the input terminal 27m is output, at this time, the data processing section 26 automatically selects the selection signal of the input terminal selection circuit 28 if it is not a+b as shown in FIG. It is determined whether the selection signal is a selection signal or not, and if it is a selection signal, the odd channel system plate thickness signal a1. m2. Performs interpolation processing using ... and converts it into a profile pattern. In the interpolation process here, a calculation of a I + a 2/2 is performed, and this calculated value is used as the signal bi of the second channel of the even channel system. The third and fifth channel signals m2°a3 are also added together and divided by a numerical value of 2, and this calculated value is used as the fourth channel signal b2. Hereinafter, interpolation processing is performed by interpolation calculation in the same manner as in the sixth step. 8th.・・・
・Check the channel signal. Therefore, under normal conditions, the odd channel system signal Signal e will be interpolated.

As is clear from FIG. 5, the interpolation process yields a signal that is substantially close to the normal state.

Next, when a failure occurs in one channel of the odd channel system, the data processing section 26 similarly controls the input terminal selection circuit 2.
Based on the b selection signal from 8, the even channel system signals bl, b2 . ... and performs interpolation processing. After performing interpolation processing, it is converted into a profile pattern and displayed on the display section 29.

In the above embodiment, as a means for interpolating the missing signal of a certain channel in one channel system, interpolation is performed sequentially using the average value of the sum value obtained by adding two adjacent channel signals of the other channel system. I tried, but
Other interpolation means may also be used. For example, interpolation may be performed using a quadratic or higher order approximation formula. Further, although an example using one multi-channel detector 21 has been described, the present invention can be similarly applied to a case where a plurality of multi-channel detectors 21, 21, . . . are used.

Further, if the plate thickness converter is installed in a relatively safe place or a place where maintenance is easy, it is sufficient to use one instead of two as in the above embodiment. Furthermore, the plurality of channels may be divided into three systems instead of two.

In addition, the present invention can be implemented with various modifications without departing from the gist thereof.

〔Effect of the invention〕

As described in detail above, according to the present invention, a plurality of serial/f, multiplexers, A-D converter circuits, etc., constituting a detection section installed in a relatively bad environment or in a remote location where maintenance is difficult, can be used. The system is divided into channel systems, and when a failure occurs in one channel system, interpolation processing is performed using signals from other channel systems to convert it into a profile pattern of the measured object. have an effect.

■ Even if one channel system fails, the profile pattern of the object to be measured can be created using signals from other channel systems.

(2) If the detection unit is installed in a bad environment, troubleshooting work can be carried out during periodic maintenance and inspections, and line processes can be made smoother.

■ There is no need to stop the line due to a failure occurring during online operation, thereby increasing system availability and minimizing damage caused by failure.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a conventional radiation thickness meter, Fig. 2 is a block diagram showing an embodiment of a radiation thickness needle according to the present invention, Fig. 3 is a flowchart showing an example of data processing, and Figs. FIG. 5 is a diagram showing the relationship between the channel and the thickness during normal operation and after performing interpolation processing due to failure. 2...Radiation source, 21...Multi-channel detector, 2
1-1~J-N...detection element, 22-1~22-N
...Norianno, 2! IA, 23B...Multiplexer, 24A, 24B...A-hi conversion circuit, 25A
, 26B... plate thickness converter, 26... data processing section,
28... Input end selection circuit, 29... Display unit. Applicant's agent Patent attorney Takehiko Suzue A

Claims (1)

[Claims] A radiation source and a multi-channel detector are placed facing each other,
The radiation transmitted from the radiation source and incident on the object to be measured is detected by a detection section such as a multi-channel detector, a multiplexer, and an A-D conversion circuit, and the detection signal from this detection section is converted into a plate thickness signal. After that, in a radiation thickness meter that measures the shape of the object by converting it into a profile/quantity turn in a data processing section, at least the detection section is divided into a plurality of channel systems and an abnormal detection signal is output. A radiation thickness meter characterized in that the shape of the object to be measured is measured by removing an output from a channel system and performing interpolation processing using a detection signal from another channel system.