JPH056861B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention can be carried out by obtaining infrared rays from a light source without the risk of explosion even when the sheet to be measured is running in an explosive atmosphere. The present invention relates to an infrared moisture measuring method and apparatus for a sheet running in an explosive atmosphere, which can quickly and accurately obtain results over a wide moisture content range.

[Prior art and its problems]

There are many processes in which it is necessary to measure and control the moisture content of seats running in explosive atmospheres. An example of this will be explained with reference to FIG. 4, which is a schematic diagram of a process for manufacturing an adhesive sheet using a solvent-based adhesive solution. While the paper-based base material 19 (e.g., polylaminated paper) is unwound from the roll 20 and run, the coater head 21 is applied with a solvent-based adhesive solution (e.g., 70% toluene-ethyl acetate mixed solvent, acrylic adhesive). 30%) is applied and dried while passing through the dryer 22, and then the laminating base material 23 is run from the other side and laminated to the adhesive coated surface, and the product 24
Roll it up. At the outlet of the dryer 22 in this step, not only the solvent but also the moisture in the base material 19 is almost zero, whereas the lamination base material 23
Since the moisture content is 6 to 7%, the product 24 tends to curl or curl due to the moisture difference between the front and back sides.
To prevent this, the base material 19 that has passed through the dryer 22 is usually humidified by a humidifier 25 to balance the moisture content on the front and back sides of the product. For this reason, it is important to accurately measure the moisture content after humidification and manage whether it is an appropriate amount or not.

Another example of a process that requires moisture measurement and management is a process in which a processed sheet is manufactured by coating a sheet with an alcohol-water mixed coating liquid and drying it. In this case as well, it is important to accurately measure and control the moisture content in order to maintain a constant quality of the product by adjusting the degree of drying by the dryer so as to leave an appropriate predetermined moisture content.

In the process of applying and drying a combustible substance such as toluene, ethyl acetate, alcohol, etc. as a solvent as exemplified above, for example, an area including part or all of the process as shown by the dashed line in FIG. is filled with these solvent vapors and an explosive atmosphere E is formed. By the way, it is preferable to measure the moisture content of the sheet by infrared moisture measurement method because of the accuracy of the measured value and the possibility of measuring many measurement points. In principle, this infrared moisture measurement method uses the infrared absorption spectrum of the material to be measured that contains moisture, and uses measurement wavelength light (light with a wavelength that is absorbed by water) and reference wavelength light (light with a wavelength that is absorbed by water). Information regarding water content is obtained by projecting light (with a wavelength that is not absorbed) onto the material to be measured and calculating the ratio of each amount of reflected light or each amount of transmitted light. Infrared moisture meters that carry out such infrared moisture measurement methods generally use incandescent bulbs or tungsten halogen lamps as light sources, and most of them have incomplete explosion-proof measures. It cannot be used to measure the moisture content of a seat running in an explosive atmosphere, as there is a risk of explosion. Therefore, in such cases, conventionally, the moisture content has been measured by sampling a piece of the sheet and using a gravimetric method, or by taking the sampled sheet out of an explosive atmosphere and using a known moisture meter. .

However, such conventional methods not only have problems with the accuracy of the measured values, but also have the problem of not being able to adequately measure and manage the moisture content of the sheet because it is extremely difficult to increase the number of measurement points. It was hot.

[Means for solving problems]

The present invention solves the above-mentioned problems of the prior art, and in order to measure moisture with high precision and freely increase the number of measurement points, the present invention makes it possible to obtain infrared rays from a light source and measure moisture using infrared rays without the risk of explosion. As a result of intensive research with the aim of providing a method and device that can instantly measure moisture content over a wide range of conditions, we have developed a method and device that uses an infrared-transmitting optical fiber in the optical path to obtain and project infrared light. It was completed after discovering that the objective could be achieved by performing only light reception in an explosive atmosphere.

That is, one aspect of the present invention is that when measuring the moisture content of a sheet running in an explosive atmosphere, light from a light source is transmitted through an interference filter and two measurements in the infrared region are performed based on the infrared absorption spectrum of the material to be measured. A wavelength light and two reference wavelengths are obtained. On the one hand, each wavelength light is projected onto the material to be measured and its reflected light or transmitted light is received and guided to a photoelectric converter. On the other hand, the light of each wavelength is projected directly onto the material to be measured, and the reflected light or transmitted light is received and guided to a photoelectric converter. On the other hand, the light of each wavelength is projected directly onto the material to be measured. The light is guided to a photoelectric converter, and an infrared transmitting optical fiber is used in the optical path to transmit and receive the light, and the variation in the light source light intensity between the measurement wavelength light and the reference wavelength light thus obtained is corrected. This invention relates to an infrared moisture measuring method for a sheet running in an explosive atmosphere (hereinafter referred to as "infrared ray moisture measuring method"), which is characterized in that the moisture content is determined by obtaining the light intensity ratio using a photoelectric conversion value, and that only the above-mentioned light emission and light reception are performed in the explosive atmosphere. (sometimes referred to as the method of the present invention)
It is.

The other two aspects of the present invention are moisture measuring devices suitable for carrying out the method of the present invention, one of which is (a) an infrared transmission type in which the light emitted from the light source is split into four or four branches; The optical fiber bundle is divided into four optical paths, and through four types of interference filters installed at the terminals of each optical path, two measurement wavelengths and two reference wavelengths in the infrared region based on the infrared absorption spectrum of the material to be measured are transmitted. means for obtaining light; (b) dividing the infrared rays transmitted through the individual interference filters into two beams for each wavelength; guiding one beam to a projection end and projecting it onto the material to be measured; Means for obtaining 8 beams with 4 wavelengths as a whole by having two or two branched infrared transmitting optical fiber bundles each having an optical shutter downstream from each interference filter to guide the fibers to a photoelectric converter. (c) means comprising an infrared transmitting optical fiber bundle for receiving reflected or transmitted light from the material to be measured at a light receiving end and guiding it to a photoelectric converter; (d) sequentially selecting the optical shutters; open and close,
means for sequentially and selectively guiding a predetermined beam to a photoelectric converter to photoelectrically convert a serial optical signal and then amplifying it with a DC amplifier and converting it into a serial analog voltage; (e) opening of the optical shutter that opens and closes first; means for generating a synchronizing pulse in synchronization with each opening of all optical shutters, and generating a sampling pulse in synchronization with each opening of all optical shutters; means for detecting the maximum peak of the analog voltage signal and converting it into a serial digital voltage signal; (g) a predetermined signal necessary for calculating the moisture content of the material to be measured by combining the synchronized pulse and the serial digital voltage signal; A means for selectively identifying water content and calculating and displaying moisture content, mainly consisting of the configurations (a) to (g) above, including a light emitting end in configuration (b), a light receiving end in configuration (c), and a means connected thereto. This relates to an infrared moisture measuring device for a sheet running in an explosive atmosphere, characterized in that only a necessary part of the optical fiber bundle is installed in the explosive atmosphere (hereinafter referred to as the first device of the present invention). ).

Furthermore, another type of moisture measuring device is: (h) Four types of interference filters are arranged on the same circumference at predetermined intervals on a rotating disk concentric with the circumference at predetermined positions close to the circumference. Two or two branched infrared-transmissive optical fiber bundles are installed from the light source to the rotating disk to separate the light emitted from the light source into two beams and guide the light toward the plate surface. During the rotation of the rotating disk, four types of interference filters pass through each beam, creating two beams for each of two measurement wavelength lights and two reference wavelength lights based on the infrared absorption spectrum of the material to be measured. total of 4 wavelengths, 8
Means for obtaining the beam: (i) the above-mentioned 2 provided from the light source to the rotating disk;
It consists of two infrared-transmissive optical fiber bundles with the optical axes of the tips aligned with the rear end of each of the book or bifurcated optical fiber bundles with a rotating disk in between, and the four types of interference filters are means for guiding one of the two beams to a light emitting end and emitting the light for each wavelength light obtained by passing through the beam, and guiding the other beam to a photoelectric converter; (j) means for guiding the other beam to a photoelectric converter; means consisting of an infrared-transmissive optical fiber bundle for receiving reflected light or transmitted light from the material at a light receiving end and guiding it to a photoelectric converter; means for generating a synchronizing pulse at a time, and generating a sampling pulse in synchronization with the timing at which each of the four types of interference filters crosses the two beams; (l) means for photoelectrically converting the serial optical signal entering the photoelectric converter; (m) means for guiding the serial analog voltage signal and the sampling pulse to a sample-and-hold circuit to detect the maximum peak of each analog voltage; (n) means for selectively identifying a predetermined signal necessary for calculating the moisture content of the material to be measured by combining the synchronized pulse and the serial digital voltage signal; The calculation/display means mainly consists of the configurations (h) to (n) above, and only the necessary parts of the transmitting end of configuration (i), the receiving end of configuration (j), and the optical fiber bundle continuous with them are used. This invention relates to an infrared moisture measuring device for a sheet while traveling in an explosive atmosphere (hereinafter sometimes referred to as the second device of the present invention), which is characterized in that it is installed in an explosive atmosphere.

[Explanation of composition and action]

Hereinafter, the structure and operation of the first and second devices of the present invention will be explained with reference to the drawings, and the method of the present invention will also be explained.

FIG. 1 is a diagram showing the main system configuration of an embodiment of the first device of the present invention, FIG. 2 is a diagram showing the system configuration of the main components of an embodiment of the second device of the present invention, and FIG. FIG. 3 is a diagram showing an example of a time series of voltage signals.

(i) First, the first device of the present invention will be explained with reference to FIG.

Structure of (a): In the drawing, 1 is a light source, preferably one that emits only infrared rays, but usually a halogen tungsten lamp or an incandescent lamp is used. 2 is a lens for converging the light emitted from the light source 1. Reference numeral 3 denotes a bundle of four or four-branched infrared transmission type optical fibers, which serves as an optical path through which light from the light source 1 that is focused by the lens 2 enters and travels as four beams. Such an infrared transmitting optical fiber used in the present invention includes, for example, a diaguide.
ST normal grade (DAIAGUIDEST, product name,
(manufactured by Dainichi Nippon Electric Cable Co., Ltd.) is shown. Reference numeral 4 denotes interference filters of different types provided at the terminals of each optical fiber 3, which transmit the light that has passed through each optical fiber 3 and convert it into infrared rays of four predetermined wavelengths in the infrared region. These four predetermined wavelengths are two measurement wavelengths and two reference wavelengths used for moisture measurement based on the infrared absorption spectrum of the material to be measured, and the measurement wavelength is 1.43 μm.
(for high moisture) and 1.95 μm (for low moisture), and 1.24 μm (for high moisture) and 1.82 μm as reference wavelengths.
(for low moisture), and therefore each of the four types of interference filters transmits the light from the light source 1 and converts it into infrared rays of the above-mentioned predetermined wavelength. In this way, the means (a) for obtaining four types of predetermined wavelength light in the infrared region using the optical fiber bundle 3 is constructed.

Structure of (b): Reference numeral 5 denotes an infrared transmission type optical fiber bundle for guiding infrared rays of a predetermined wavelength transmitted through each interference filter 4 to a predetermined location. This optical fiber bundle 5 is provided as two or two branched optical fiber bundles 5a and 5b on the downstream side of each interference filter 4, and divides the infrared rays of each of the four wavelengths into two beams for a total of 8 beams. Two beams are obtained. And 2
One of the optical fiber bundles 5a among the two optical fiber bundles 5 guides one beam to a position close to the material to be measured 11 and emits light from there, so its terminal is installed as a light projection end 5aa at a position close to the material to be measured 11. The other optical fiber bundle 5b is connected to a photoelectric converter 13 to guide the other beam thereto. Reference numeral 6 denotes an optical shutter, which is provided in both optical fiber bundles 5a and 5b. By opening and closing the optical shutter 6, the beam flows or disappears within the optical fiber bundles 5a, 5b. In this way, a means (b) is constructed in which the optical fiber 5 is used downstream of each interference filter 4 to perform the respective functions.

Configuration of (c): 7 is an infrared transmission type for receiving reflected or transmitted infrared light (FIG. 1 shows the case of only reflected light) from the material to be measured 11 and guiding it to the photoelectric converter 13. The light receiving end 7a of the optical fiber bundle is placed at a light receiving position close to the material to be measured 11, thus forming the means (c).

Configuration of (d): 13 is a photoelectric converter in which the temperature of the light receiving element PbS is kept constant by an electronic controller;
Thermal stability is ensured. Two beams for each predetermined wavelength obtained by the interference filter 4 are input to the photoelectric converter 13 through the following paths. That is, one beam passes through the optical fiber bundle 5a and is projected onto the material to be measured 11, and then the reflected light or transmitted light is input via the optical fiber bundle 7, and the other beam passes through the optical fiber bundle 5b. It is now entered as is. 14 is a DC amplifier that receives a voltage signal from the photoelectric converter 13 and amplifies it. An optical shutter 6 is provided in each of the optical fiber bundles 5a and 5b, and by sequentially selectively opening and closing the optical shutter 6, an input serial optical signal is photoelectrically converted, and then DC amplified and converted into a serial signal. Can be converted to analog voltage. The means (d) is configured in this way.

Configuration (e): 8 and 9 are photo sensors, which may be either reflective or transmissive. There is only one photosensor 8 to generate a synchronizing pulse in synchronization with the opening of the optical shutter 6 that opens and closes first, and the photosensor 9 generates a sampling pulse in synchronization with the opening of all the optical shutters 6. Each optical shutter 6 is installed in order to generate the image. The means (e) is configured in this way.

Configuration of (f): 12 is an OR circuit which outputs a pulse every time a pulse is generated in any of the photosensors 9. 15 is a sample and hold circuit;
By inputting the output of the OR circuit 12 and the output of the DC amplifier 14 to the input stage, the DC amplifier 14 is synchronized with the sampling pulse from the OR circuit 12.
The individual maximum values of the serial analog voltages from are detected and output. Reference numeral 16 denotes an analog-to-digital conversion interface, which converts the serial analog maximum voltage inputted from the sample-and-hold circuit 15 into a serial digital voltage and outputs it. The means (f) is configured in this way.

Configuration (g): Reference numeral 17 is an input/output interface that takes in synchronizing pulses from the photosensor 8. Reference numeral 18 is a calculation/display unit that receives the synchronizing pulse from the input/output interface 17, and immediately after that receives a data string consisting of 8 serial digital signals as one block, and combines these to be described later. As illustrated, a predetermined signal necessary for calculating the moisture content of the material to be measured is selectively identified, and the moisture content is calculated and displayed. Means (g) is thus constructed.

The first device of the present invention is mainly composed of the above-mentioned means (a) to (g), and, for example, the position P in FIG. As shown in FIG. 1, a light emitting end 5aa, a light receiving end 7a, and an optical fiber bundle 5 continuous thereto
Only the necessary parts of a and 7 are installed in the explosive atmosphere E, and that part is installed outside the explosive atmosphere E.

The operation of the first device of the present invention is as follows. When each device is put into operation and the optical shutter 6 is opened for the first time, a synchronization pulse and a sampling pulse are generated by the photosensors 8 and 9, respectively, and are sent to the input/output interface 17 and the sample-and-hold circuit 15, respectively. A predetermined wavelength (e.g. 1.24 μm)
The light passes through the optical fiber bundle 5a and is projected onto the material to be measured 11 from the light projecting end 5aa of the terminal, and the reflected light or transmitted light is received by the light receiving end 7a of the optical fiber bundle 7.

The reflected or transmitted light from the material to be measured 11 received in this way passes through the optical fiber bundle 7 and is guided to the photoelectric converter 13, and then to the DC amplifier 14.
An analog voltage corresponding to the amount of reflected light or transmitted light that is accurately related to the moisture content of the material 11 to be measured is generated. This analog voltage is input to the sample-and-hold circuit 15 together with the sampling pulse generated by the photosensor 9, and the maximum value of the voltage is digitized by the analog-to-digital conversion interface 16 and then passed through the input/output interface 17. Together with the synchronization pulse from the photosensor 8, it is taken into the calculation/display section 18 and becomes data _D1 based on reflected light or transmitted light.

The first optical shutter 6 opened is closed, and then the second optical shutter 6 provided in another optical fiber bundle 5b that passes the same wavelength light as above is closed.
When opened, the wavelength light passes through the optical fiber bundle 5b, passes through the photoelectric converter 13 and the DC amplifier 14, and generates an analog voltage corresponding to the light intensity of the light source 1 together with the sampling pulse generated by the photosensor 9 in the same way as above. The voltage is input to the sample-and-hold circuit 15, and the maximum value of the voltage is converted into digital data by the analog-to-digital conversion interface 16 and taken into the calculation/display unit 18.
(The photo sensor ₈ does not operate after the second one, so the calculation/display unit 1 does not operate until the first optical shutter 6 opens again.)
8, the synchronization pulse is not confirmed).

Similarly, other wavelengths (for example, 1.43 μm,
2 for each of the light of 1.82μm and 1.92μm)
The two optical shutters 6 are sequentially opened and closed to input digital data D ₃ to D ₆ into the calculation/display section 18 .

An example of the time-series relationship among the synchronizing pulse, sampling pulse, and analog voltage generated by sequentially opening and closing the first to eighth optical shutters 6 is shown in FIG. In FIG. 3, A indicates a synchronizing pulse, B indicates a sampling pulse, and C indicates an analog voltage. A serial analog voltage having such a relationship is input to the sample-and-hold circuit 15 together with the sampling pulse, and the analog voltage is
The individual maximum values of the voltages are converted into digital data by the digital conversion interface 16,
Each of the data D ₁ to _{D 8} shown below is calculated as one block of data string for each synchronization pulse from the photosensor 8 that has passed through the input/output interface 17.
The image is captured on the display section 18.

The order in which the optical shutters 6 are opened and closed does not necessarily need to be performed for each wavelength of light as described above, and the data obtained by opening and closing the eight optical shutters 6
The order of opening and closing may be arbitrary as long as D ₁ to _{D 8} correspond to D ₁ to _{D 8} in the formula for calculating moisture content.

These data D ₁ to _{D 8} are selectively identified in the calculation/display unit 18, and, for example, as explained below, equations (1) to (3) are selected in a predetermined order, and the moisture content is calculated. It will be displayed.

D ₁ : Data based on reflected light or transmitted light from the material to be measured with a wavelength of 1.24 μm D ₂ : Data based on light for light intensity fluctuation correction with a wavelength of 1.24 μm D ₃ : Reflected light from the material to be measured with a wavelength of 1.43 μm Or data based on transmitted light D ₄ : Data based on light for correcting light intensity fluctuations with a wavelength of 1.43 μm D ₅ : Data based on reflected light or transmitted light from the material to be measured with a wavelength of 1.82 μm D ₆ : Light amount with a wavelength of 1.82 μm Data based on light for compensation of fluctuations D ₇ : Data based on reflected light or transmitted light from the material to be measured at a wavelength of 1.95 μm D ₈ : Data based on light for compensation of light intensity fluctuations at a wavelength of 1.95 μm D ₃ /D ₇ × D ₈ /D ₄ (1) D ₅ /D ₇ ×D ₈ /D ₆ (2) D ₁ /D ₃ ×D ₄ /D ₂ (3) The second term in each equation is a correction term for changes in light amount. This method takes advantage of the fact that the light projected onto the material to be measured 11 and the light for correcting light intensity fluctuations are proportionally affected.

Determine the approximate moisture content of the material to be measured according to the value of equation (1), and if this value is larger than a certain value, it is considered to be low moisture, and the moisture content is calculated using equation (2). If it is small, it is assumed that the moisture content is high and the moisture content is calculated using equation (3), and if it is close to a constant value, the moisture content is calculated from both equations (2) and (3).

This constant value can be determined as appropriate based on technical experience, but
For example, values determined by the transmittance of the individual interference filters 4 whose dominant wavelengths are 1.43 μm and 1.95 μm and the infrared absorption spectrum of the material 11 to be measured can be adopted.

(ii) Next, a second apparatus of the present invention will be explained with reference to FIG.

Structure of (h): In the drawing, 1 is a light source, 2 is a lens, and these are the same as the first device of the present invention. 3' is a bundle of two or two branched infrared-transmissive optical fibers, and the light from the light source 1, which is focused by the lens 2, enters and becomes two beams, forming an optical path that travels from the light source 1 to the next one. It even has a rotating disk to explain. Reference numeral 10 denotes a rotating disk, and four types of interference filters 4 are arranged at predetermined intervals on the same circumference concentrically with the rotating disk.
This is the same as that described in connection with the apparatus of the present invention. The terminals of the optical fiber bundle 3' are arranged at two predetermined positions toward the plate surface close to the circumference where the interference filter 4 is arranged (hereinafter, these positions are referred to as the optical fiber bundle 3'). ), each interference filter 4 traverses the two beams emitted from these two optical fiber bundles 3', so that the In total, eight beams with four wavelengths are obtained, two beams for each of the four wavelengths in total, including one measurement long beam and two reference wavelength beams. Since these eight beams must be obtained at different times because the data for each beam must be obtained separately, the terminal position of the optical fiber bundle 3' is such that an interference filter 4 is placed in the optical path of the two beams exiting therefrom at the same time. These two locations do not exist, and can be determined in various ways based on the arrangement of the interference filter 4 on the rotating disk 10. Generally, four interference filters 4 have α°,
When the optical fiber bundles 3' are arranged at intervals of β°, γ°, and δ°, it is sufficient that the terminals of the optical fiber bundle 3' are arranged at intervals of θ° that do not match any of these. Standardly, four interference filters 4 are arranged at equal intervals of 90 degrees, and it is sufficient that the terminal positions of the two optical fiber bundles 3' are at intervals other than 90 degrees. When the angle is 45°, two beams of light of a predetermined wavelength are obtained successively from the same interference filter 4, and four types of interference filters are sequentially obtained from the other interference filters 4 during one rotation of the rotating disk 10. A total of 8 beams of 4 wavelengths, 2 beams for each of 4 wavelengths, are obtained at equal time intervals by the constant rotation of the rotating disk 10. In this way, the means (h) is constructed.

Structure (i): 5' is an infrared transmission type optical fiber bundle for guiding light of a predetermined wavelength transmitted through the interference filter 4 to a predetermined location. This optical fiber bundle 5' is a two or bifurcated optical fiber bundle 5a whose tips are coaxially sandwiched between the terminals of the two optical fiber bundles 3' which are the optical path of the light source light and the rotating disk 10. ',5
b', and the terminal of one optical fiber bundle 5a' serves as a light emitting end 5aa' for the material to be measured 11.
One of the two beams is projected onto the material to be measured 11, and the other optical fiber bundle 5b' is placed close to the photoelectric converter 13.
is connected to the other beam and directs the other beam to it. Therefore, as the rotating disk 10 rotates, each wavelength light that has passed through the four types of interference filters 4 is guided to the above-mentioned predetermined location. In this way, the means (i) is configured.

Configuration (j): Similar to the means (c) of the first device of the present invention, the optical fiber bundle 7 receives reflected light or transmitted light from the material 11 to be measured at a position close to the material 11 to be measured. A means (j) for guiding the light to the photoelectric converter 13 is constructed.

Configuration (k): The same photosensors 8 and 9 as explained in the means (e) of the first device of the present invention are used, and the rotating disk 1
One photosensor 8 generates a synchronous pulse every rotation in synchronization with the rotation of the light source 1, and each of the four interference filters 4 generates a sampling pulse in synchronization with the timing at which the two beams from the light source 1 cross. Means (k) is constructed by installing two photosensors 9 for generating the light.

Configuration (l): A photoelectric converter 13 and a DC amplifier 14 are installed in the same manner as explained in the means (d) of the first device of the present invention, and the material to be measured 1 is input to the photoelectric converter 13.
Means (l) for converting a serial optical signal from 1 into a serial analog voltage signal is constructed.

Configuration of (m): Like the means (f) of the first device of the present invention, OR circuit 1
2. Means (m) for detecting the maximum peak of the serial analog voltage converted and amplified by the means (l) using the sample-and-hold circuit 15 and the analog-to-digital conversion interface 16 and converting it into a serial digital voltage signal; ) is configured.

Configuration of (n): Similar to the means (g) of the first device of the present invention, means for calculating and displaying the moisture content of the material to be measured 11 ( n) is configured.

The second device of the present invention is mainly composed of the above-mentioned means (i) to (n), and like the first device of the present invention, as shown in FIG. Only the necessary portions of the light receiving end 7a and the optical fiber bundles 5a' and 7 connected thereto are installed within the explosive atmosphere E, and the other portions are installed outside the explosive atmosphere E.

The operation of the second invention device is as follows.

An example will be explained in which four interference filters 4 are arranged at equal intervals of 90 degrees on a rotating disk and the end intervals of the optical fiber bundles 3' are 45 degrees. When the rotating disk 10 is rotated with each device in operation, when the first interference filter 4 first crosses the first of the two beams coming from the two terminals of the optical fiber bundle 3', the photosensor Synchronizing pulses and sampling pulses are generated by 8 and 9, respectively, and are inputted to the input/output interface 17 and sample-and-hold circuit 15, respectively. .mu.m) passes through the optical fiber bundle 5a'.

Thereafter, the process is exactly the same as the operation when the optical shutter 6 is first opened and closed in the above description of the operation of the first device of the present invention. That is, the light that has passed through the optical fiber bundle 5a' is projected onto the material to be measured 11 from the light emitting end 5aa', and its reflected light or transmitted light is received at the light receiving end 7a, and the light thus received is Photoelectric conversion is performed, and the detected maximum value is converted into digital data and calculated and processed together with the synchronization pulse.
The light is taken into the display unit 18 and becomes data _D1 based on reflected light or transmitted light.

Next, when the same interference filter 4 crosses the second beam, the same wavelength light as above passes through the optical fiber bundle 5b' and is directly input to the photoelectric converter 13, and a sampling pulse is generated at the photosensor 9. Hereinafter, in exactly the same manner as in the case of opening and closing the second optical shutter 6 in the above description of the operation of the first device of the present invention, light of a predetermined wavelength passes through the optical fiber bundle 5b' and is photoelectrically converted, and the light source 1
The maximum value of the analog voltage corresponding to the amount of light is converted into digital data and taken into the calculation/display unit 18, and becomes data D ₂ for correcting the amount of light.

Thereafter, the other interference filters 4 sequentially cross the two beams in the same way, and each data D ₁ to _D8 is taken into the calculation/display unit 18 as one block of data string. Four interference filters 4 on rotating disk 10
Due to the relationship between _{the arrangement of} There is no problem as long as it corresponds to ₈ . The moisture content of these data D ₁ to _{D 8} is calculated and displayed in exactly the same manner as described above regarding the operation of the first apparatus of the present invention.

In addition, in the conventionally used infrared moisture meter,
Only two types of interference filters were installed, one for the measurement wavelength and one for the reference wavelength, and depending on the moisture content, it was necessary to replace the interference filters, and the measurement had to be interrupted each time. The first and second apparatuses of the present invention can instantly measure moisture content over a wide range.

As can be seen from the above description, the relationship between the first and second devices of the present invention and the method of the present invention is as follows. That is, the means (a) and the means (h) transmit the light from the light source 1 through the interference filter 4 and pass through the material to be measured 11.
This is a device for obtaining measurement wavelength light and reference wavelength light based on the infrared absorption spectrum of It is a device for projecting light onto a material 11, receiving the reflected light or transmitted light, and guiding it to a photoelectric converter 13, and on the other hand directly guiding it to the photoelectric converter 13 for correction of fluctuations in the amount of light from the light source. Bundles 3, 5, and 7 and optical fiber bundles 3', 5', and 7 use infrared-transmissive optical fibers in the above-mentioned optical path, making it possible to only transmit and receive light in an explosive atmosphere. Means (d), (e), (f) and (g) and means (k), (l), (m) and (n) are the obtained measurement wavelength light and the reference This is a device for determining moisture content by obtaining a light intensity ratio with wavelength light corrected for light source light intensity fluctuations from a photoelectric conversion value. Therefore, it can be seen that the first and second apparatuses of the present invention are suitable apparatuses for carrying out the method of the present invention.
In addition, if there is a lot of water vapor around the moisture measurement point and it interferes with infrared moisture measurement, a small chamber is provided that almost surrounds the light emitting end 5aa or 5aa' and the light receiving end 7a up to the vicinity of the material to be measured 11, and dry gas is supplied there. It is sufficient to carry out measurements while supplying water vapor and excluding water vapor.

〔effect〕

The present invention uses an optical fiber that efficiently transmits infrared rays along the entire optical path from the light source to the photoelectric converter to measure the moisture content of a sheet traveling in an explosive atmosphere. By applying the infrared moisture measurement method by obtaining infrared rays and only projecting and receiving the light in an explosive atmosphere, the following effects can be obtained.

(b) Even though the seat is running in an explosive atmosphere, it is possible to use an infrared moisture meter without the risk of explosion. Measurements can be taken.

(b) Optical fibers are used in the optical path to transmit the light from the light source through an interference filter to obtain infrared rays, and the optical path is configured in various ways to accommodate any case with a wide range of moisture content. Various types of interference filters can be arranged in advance, thereby eliminating the need to replace interference filters depending on the moisture content.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the main system configuration of an embodiment of the first device of the present invention, FIG. 2 is a diagram showing the system configuration of the main components of an embodiment of the second device of the present invention, and FIG. Diagram 4 showing an example of a time series of voltage signals
The figure is a schematic diagram of the adhesive sheet manufacturing process. 1... Light source, 2... Lens, 3, 3'... Optical fiber bundle, 4... Interference filter, 5, 5'...
...Optical fiber bundle, 5a, 5a'...One optical fiber bundle of two or two branches, 5aa, 5
aa'... Light emitting end, 5b, 5b'... The other of two or two branched optical fiber bundles, 6... Optical shutter, 7... Optical fiber bundle, 7a... Light receiving end, 8... Photosensor, 9... Photosensor,
10... Rotating disk, 11... Material to be measured, 12...
...OR circuit, 13...Photoelectric converter, 14...DC amplifier, 15...Sample and hold circuit,
16... Analog-to-digital conversion interface, 17... Input/output interface, 18
...Calculation/display unit, 19... Base material, 20... Roll, 21... Coater head, 22... Dryer, 23... Base material for lamination, 24... Product, 25...
...Humidifier, A...Synchronization pulse, B...Sampling pulse, C...Analog voltage.

Claims (1)

[Scope of Claims] 1. When measuring the moisture content of a sheet running in an explosive atmosphere, light from a light source is transmitted through an interference filter to generate light with two measurement wavelengths in the infrared region based on the infrared absorption spectrum of the material to be measured. and two reference wavelength lights are obtained, on the one hand, each wavelength light is projected onto the material to be measured, and the reflected light or transmitted light is received and guided to a photoelectric converter, and on the other hand, the light of each wavelength is directly emitted to correct for fluctuations in the light source light intensity. The light is guided to a photoelectric converter and the light is emitted and received using an infrared transmitting optical fiber in the optical path, and the light intensity is corrected for variations in the light source light intensity between the measurement wavelength light and the reference wavelength light obtained in this way. A method for measuring infrared moisture in a sheet running in an explosive atmosphere, characterized in that the moisture content is determined by obtaining a ratio from a photoelectric conversion value, and that only the above-mentioned light emission and light reception are performed in an explosive atmosphere. 2 (a) The light emitted from the light source is divided into four optical paths using four or four-branched infrared-transmitting optical fiber bundles, and four optical fibers are provided at the terminals of each optical path.
2 in the infrared region based on the infrared absorption spectrum of the material being measured through different types of interference filters.
(b) dividing the infrared rays transmitted through each of the interference filters into two beams for each wavelength, and guiding one beam to the light emitting end to direct the infrared light to the material to be measured; It has two or bifurcated infrared-transmissive optical fiber bundles each having an optical shutter on the downstream side from each interference filter, for projecting light onto one beam and guiding the other beam to a photoelectric converter, (c) means for receiving reflected or transmitted light from the material to be measured at a light receiving end and guiding it to a photoelectric converter; (d) sequentially selectively opening and closing the optical shutter;
means for sequentially and selectively guiding a predetermined beam to a photoelectric converter to photoelectrically convert a serial optical signal and then amplifying it with a DC amplifier and converting it into a serial analog voltage; (e) opening of the optical shutter that opens and closes first; means for generating a synchronizing pulse in synchronization with each opening of all optical shutters, and generating a sampling pulse in synchronization with each opening of all optical shutters; means for detecting the maximum peak of the analog voltage signal and converting it into a serial digital voltage signal; (g) a predetermined signal necessary for calculating the moisture content of the material to be measured by combining the synchronized pulse and the serial digital voltage signal; means for selectively identifying water content and calculating and displaying moisture content, mainly consisting of the configurations (a) to (g) above, including a light emitting end in configuration (b), a light receiving end in configuration (c), and a means for calculating and displaying moisture content. An infrared moisture measuring device for a sheet running in an explosive atmosphere, characterized in that only a necessary part of a continuous optical fiber bundle is installed in the explosive atmosphere. 3 (h) Four types of interference filters are arranged on the same circumference at predetermined intervals, and the light emitted from the light source is transmitted to two predetermined positions close to the circumference on a rotating disk concentric with the circumference. It has two or two branched infrared-transmissive optical fiber bundles from the light source to the rotating disk to guide the light into two beams and emit the light toward the plate surface. By passing each beam through four types of interference filters, two measurement wavelengths and two reference wavelengths each have two bits each, based on the infrared absorption spectrum of the material being measured, for a total of four wavelengths, eight bits each.
Means for obtaining the beam: (i) the above-mentioned 2 provided from the light source to the rotating disk;
It consists of two infrared-transmissive optical fiber bundles with the optical axes of the tips aligned with the rear end of each of the book or bifurcated optical fiber bundles with a rotating disk in between, and the four types of interference filters are means for guiding one of the two beams to a light projecting end and projecting it onto the material to be measured, and guiding the other beam to a photoelectric converter for each wavelength light obtained by passing through the ) Means consisting of an infrared-transmissive optical fiber bundle for receiving reflected light or transmitted light from the material to be measured at a light receiving end and guiding it to a photoelectric converter; means for generating a synchronizing pulse every rotation, and generating a sampling pulse in synchronization with the timing at which each of the four types of interference filters crosses the two beams; (l) a serial pulse input to the photoelectric converter; (m) means for photoelectrically converting an optical signal and then amplifying it with a DC amplifier to convert it into a serial analog voltage signal; means for detecting and converting peaks into a serial digital voltage signal; (n) combining said synchronized pulse and said serial digital voltage signal to selectively identify a predetermined signal necessary for moisture content calculation of the material under test; , means for calculating and displaying moisture content, mainly consisting of the configurations (h) to (n) above, including a light emitting end of configuration (i), a light receiving end of configuration (j), and an optical fiber bundle connected thereto. An infrared moisture measuring device for a seat while traveling in an explosive atmosphere, characterized in that only necessary parts are installed in the explosive atmosphere.