JPS60143705A - Plate-thickness measuring apparatus using gray memory - Google Patents

Abstract

PURPOSE:To measure the thickness of a plate highly accurately, by providing a radiation projecting device, an analog-signal detecting part, analog to digital conversion part and a text file part for transmittance to plate-thickness conversion, and obtaining and outputting the plate thickness by an analyzing part. CONSTITUTION:A sample 1 is mounted on a table 2, which can be moved in the directions of the X axis and the Y axis that are crossed at right angles. The directions and position are detected by detectors 3 and 4. The output signals are supplied to an operation part 5. An ultra-soft X-ray projecting device 6 is provided under the table 2. A detector 7 is arranged so that it is aligned with an ultra-soft X-ray beam. The output analog signal of the detector 7 is converted into 64 gradations or more by an analog to digital converter 8. The result is stored in a gray memory 9. Data from a text file part 11 for transmittance to plate-thickness conversion is supplied to an analyzing part 10. The plate thickness is obtained from an output part 12. Thus the measurement can be performed highly accurately at a high speed in two dimensions.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plate thickness measuring device, and particularly to a plate thickness measuring device capable of measuring the plate thickness of various metal plates with high precision and high speed.

There is a need to measure the thickness of metal plates such as steel plates with high accuracy and high speed, for example, in experiments to measure the reduction in thickness of corrosion test pieces, and online to manage the thickness of products. . Devices conventionally used to measure plate thickness include ultrasonic thickness gauges and automatic electronic micrometers, both of which measure local plate thickness. Further, these conventional plate thickness measuring devices have the disadvantage of poor measurement accuracy and lack of reproducibility, especially when the plate thickness is thin. Another disadvantage is that it takes a long time to measure, making it difficult to use for online thickness measurements. In addition, since it is possible to only measure the thickness locally, that is, in a -dimensional manner, it is not possible to measure the two-dimensional distribution of the thickness over the entire surface of a corrosion test piece, for example, and it is difficult to obtain sufficiently useful data regarding the thickness. There is also the drawback that it is not available.

The object of the present invention is to eliminate the drawbacks of the conventional plate thickness measuring apparatus described above, and to provide a plate thickness measuring apparatus that can two-dimensionally measure plate thickness with high precision and high speed even for samples with a plate thickness of 1111I11 or less. This is what we are trying to provide.

The plate thickness measuring device of the present invention includes a fi radiation irradiation device that irradiates a sample whose plate thickness is to be measured with a radiation beam such as ultra-soft X-rays, X-rays, and γ-rays as a spot, and a detection section that outputs an analog signal representing the transmittance of radiation passing through the sample, an analog-to-digital conversion section that converts this analog signal into a multi-tone digital signal, and a a text file section for transmissivity-plate thickness conversion that stores a predetermined relationship between the magnitude of a multi-gradation digital signal and the plate thickness; a digital signal from the analog-digital conversion section; It includes a transparency-thickness conversion analysis section that calculates the thickness based on the text file from the conversion text file section, and an output section that outputs the thickness determined by the transparency-thickness conversion analysis section. It is characterized by the ability to grow.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a diagram showing the overall configuration of an embodiment of the plate thickness measuring device of the present invention. In FIG. 1, a sample 1 whose thickness is to be measured is placed on a table 2.

This table 2 is disposed so as to be movable in X-axis and Y-axis directions that are orthogonal to each other, and the amount of this movement is detected by X-axis and Y-axis position detectors 3 and 4. table 2
A known drive mechanism for moving in the axial and Y-axis directions can be used. Furthermore, although the position detectors 3 and 4 are equipped with differential coils connected to a table in this embodiment, optical or magnetic encoders may also be used. The output signals of the position detectors 3 and 4 in the X-axis and Y-axis directions of the temple are supplied to the calculation unit 5 to calculate the position information of the daple.

An opening 2a is provided in the center of the table 2, and a super-soft X-ray irradiation device 6 for irradiating the sample 1 with a super-soft X-ray beam is arranged below the opening 2a. This ultra-soft X-ray beam W6 is equipped with an ultra-soft X-ray generator and a pinhole device that converts the generated ultra-soft X-rays into a small-diameter beam. ! Allows irradiation as a U spot.

In addition, above the table 2, there is a super soft X that has passed through the sample 1.
A detector 7 for detecting rays is arranged so as to be aligned with the ultra-soft X-ray beam. The analog signal output from the detector 7 is converted into a digital signal with 64 or more gradations, preferably 128 gradations, in an analog-digital converter 8. This digital signal is further supplied to the gray memory 9 and stored there.

At this time, the position information from the calculation unit 5 is supplied to the gray memory 9 to control its storage position, and the measured digital values at each point within the two-dimensional area of the sample 1 are stored at predetermined address positions. The digital values stored in the gray memory 9 are read out to the transparency-to-thickness conversion analysis section 10 and the thickness is calculated. At this time, the transparency-to-thickness conversion text file section 1
1, the information of a desired text file is supplied to the tension-to-plate thickness conversion analysis section 10, and the plate thickness is calculated based on this text file. This conversion analysis operation will be described in detail later. The plate thickness determined in this way is supplied to a printer or printer 12, which includes an ivy, to display, for example, the plate thickness determined two-dimensionally over the entire surface of the sample 1 as a single image. It is possible to draw a contour map of plate thickness.

When the ultra-soft X-rays from the ultra-soft X-ray irradiation device 6 pass through the sample to be measured 1, the transmittance changes depending on the plate thickness t. The relationship approximately follows the following equation, which is Lamber's - Beer's law.

Here, 1 is the transmittance when the plate thickness is t, to is the transmittance when [=0, and is a coefficient. In the present invention, the plate thickness t is determined based on such a principle. The digital value read out from the gray memory 9 to the transmittance-thickness conversion analysis unit 10 represents the transparency, that is, the transmission intensity, of the ultra-soft X-rays that pass through the sample 1. Calculate the transmittance by correcting errors due to uneven irradiation at each part. On the other hand, the transparency-thickness conversion text file part 11
To do this, the relationship between transmittance and plate thickness is measured in advance for several types of standard samples, and this relationship is stored as a text file. In each text file, transparency is used as a parameter, and a plate thickness value corresponding to each transparency value is given. A text file corresponding to the sample to be measured 1 is selected from the text file section 11 for translucency-to-plate thickness conversion, and its contents are transferred to the translucency-to-plate thickness conversion analysis section 10.
The conversion analysis unit 10 calculates the plate thickness for the transmittance after correcting errors due to uneven irradiation as described above. In this case, when the analog-digital converter 8 digitally converts the output signal of the detector 7 at 256 gradations, changes in the plate thickness can be measured with high accuracy of about ±5 μm.

Next, the results of measuring the thickness reduction of the °C corrosion test piece using the above-mentioned plate thickness measuring device of the present invention will be shown. The sample material is 2 on one side.
spccmit plated with ln at a rate of 0 g/m2
-1W x width x lcMfi O, 7x70x150 (m
The method used in m) was used. After applying a 5 μm cationic electrolyte coating, it was subjected to a composite corrosion test. That is, a cycle of keeping the sample at 50° C. and humidity in a dry atmosphere for 21 hours and then keeping it in a humid atmosphere at 50° C. for 2 hours each time was repeated 150 times.

After corrosion, the sample was derusted with an ammonium citrate solution, and the plate thickness was measured over the entire surface using the plate thickness measuring device of the present invention. Figure 2 shows the test piece after corrosion. After measuring the plate thickness in this manner, a contour map showing changes in plate thickness at intervals of 0.1 mm was displayed on the output unit 12 as shown in FIG. As is clear from the contour diagram in Fig. 3, the plate thickness measuring device of the present invention can measure up to 1 m with extremely high accuracy.
It is possible to two-dimensionally measure the thickness of a thin sample of less than m.

The present invention is not limited to the embodiments described above, but can be modified and modified in many ways. For example, in the embodiment described above, the output digital value of the analog-to-digital converter is stored in the gray memory, but if only online thickness measurement is to be performed, the gray memory can be omitted and the digital value can be converted immediately. It can also be supplied to the analysis department. Further, in the above-described embodiment, the sample is irradiated with ultra-soft X-rays, but radiation such as X-rays or γ-rays may also be used. Generally, when the thickness of the sample is thin, it is advantageous to use ultra-soft X-rays and set t=h. Further, in the above example, only the thickness of the sample was measured, but it is also possible to detect minute pinholes existing in the sample. In this case, by detecting pinholes two-dimensionally over the entire surface of the sample, it is possible to simultaneously measure the number of pinholes, depth distribution, position, etc., which provides a variety of useful information that could not previously be obtained. data can be obtained.

Furthermore, in the above-mentioned embodiment, the ultra-soft X-rays that passed through the sample were directly detected by the detector to express the degree of penetration and extract the J analog signal, but the ultra-soft X-rays that passed through the sample were recorded by a film. However, after development, the film may be processed by a removal device and an analog signal obtained may be supplied to an analog-to-digital converter via an input terminal. In this case, the degree of blackening of the developed film will represent the transmittance, and the level of the 1fσ image signal will represent the transmittance, so from now on, the same process as described above will be performed to measure the plate thickness. can do.

As mentioned above, if the plate thickness measuring device of the present invention is used,
A radiation beam is irradiated onto the sample in spots, and the transmittance is calculated as a multi-gradation digital value, based on a text file for transmittance-thickness conversion that shows the relationship between the transmittance and the plate thickness set in advance. Since the thickness of the sample is reduced by using the same method, the thickness of the sample can be measured two-dimensionally with high precision and at high speed. In addition, a number of text files for transmittance-to-plate thickness conversion are prepared, and the text file is selected and used according to the sample to be measured, making it possible to quickly measure the plate thickness of various samples. .

Furthermore, since the plate thickness can be measured two-dimensionally over the entire surface of the sample, useful data such as a contour map of the plate thickness can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the configuration of an embodiment of the plate thickness measuring device of the present invention, Fig. 2 is a diagram showing the surface condition of a corroded test piece, and Fig. 3 is a diagram showing the test piece shown in Fig. 2. FIG. 3 is a contour map of the plate thickness measured using the device of the present invention. 1... Sample 2... Table 3.4... X-axis and Y-axis direction position detector 5... Calculation unit 6... Super soft X-ray irradiation device 7... Ultra soft X-ray detection Analog-digital converter 9... Gray memory 10... Transparency-to-plate thickness conversion analysis section 11... Transparency-to-plate thickness conversion text file section 12
...Output section. (No change to the contents of the drawings) Procedural amendment - document (method) % formula % 1. Indication of the incident 1988 Patent Application No. 250302 2. Name of the invention Plate thickness measuring device using gray memory 3. Correction Patent applicant (125) Kawasaki Steel Corporation Japan Regulator Co., Ltd. 5 Date of amendment order August 27, 1980 6 Subject of amendment ``Brief explanation of drawings'' column of the specification , "Drawing" 7. Contents of the amendment (as attached) l. In the specification, page 1, O, line 19, "Figure 2 shows the state of the surface of a corroded test piece.""A diagram showing the condition of the thickness of the test piece as an XS photograph."

Claims (1)

[Claims] 1. Ultra-soft X-rays and X-rays for the sample whose plate thickness is to be measured. Radiation that irradiates a radiation beam such as gamma rays as a spot
A JJ ray irradiation device, a detection unit that outputs an analog signal representing the degree of penetration of radiation passing through the sample according to the thickness of the sample, and an analog-digital conversion unit that converts this analog signal into a multi-gradation digital signal. and a text file section for transparent plate thickness conversion that stores predetermined relationships such as the magnitude of multi-gradation digital signals and plate thicknesses for various samples;
a transparency-plate conversion analysis section that calculates the plate thickness based on the digital signal from the analog-to-digital conversion section and the text file from the text file section for translucency-plate thickness conversion; - A plate thickness measuring device using gray memory, characterized by comprising an output unit that outputs the plate thickness determined by the plate thickness conversion analysis unit.