JP2004061389A - Transmissivity measuring method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for determining transmissivity by directly measuring a measuring object itself by measuring transmissivity of a cylindrical capillary of a cell and a filter having light transmissivity without substituting it with transmissivity of a plate-like filter. <P>SOLUTION: This transmissivity measuring method makes the light from a light source incident in the capillary as a parallel light flux 9 by placing the light source outside the capillary and a light receiving surface inside the capillary, and receives an emitting light flux 10 emitted by passing through a tube wall by the light receiving surface, and sets the area of the light receiving surface equal to the cross-sectional area of the parallel light flux, and puts the light receiving surface in a capillary central position 12. <P>COPYRIGHT: (C)2004,JPO

Description

【００２３】
即ち、本発明者らの得た新たな知見は、表１に示した細管の中央の位置での出射光束（Ｃ）に対する平行光束（Ａ）の比である。表に見る通り、細管の中央の位置での出射光束（Ｃ）に対する平行光束（Ａ）の比は１を超えないものである。したがって、細管の中央の位置における出射光束（Ｃ）の単位面積当たりの光強度は、入射する平行光束（Ａ）の単位面積当たりの光の強度に等しいか、又は０．１％以内の誤差であることが判明した。特に入射する平行光束が直径５ｍｍを超えない場合、細管中央位置での出射光束（Ｃ）と、平行光束（Ａ）の断面積は等しくなっているため、正確な透過率測定が可能であることが判る。
【００２４】
前述した従来の積分球による測定例からは、管壁（６）を透過した光を受光する場合、細管凹面へ出射した直後の光を受光することが想定されるが、表１に示すように、出射直後の出射光束（Ｂ）に対する平行光束（Ａ）の比は１より大である。従って、管壁に近接する位置で受光すると、単位面積当たりの光の強度（密度）は、入射する平行光束よりもかえって高い値が出る結果となっている。このことから、平行光束（Ａ）に対し、受光面を細管中央位置（１２）に置くことが好適であると考えられる。
【００２５】
そこで、表１の計算データを得るに至った光学的考察を、図３を用いて説明する。なお、図３の（ａ）において、細管の中心を通る平行光束の光軸をｘ軸、細管の中心を通り前記光軸に垂直な軸をｙ軸とし、ｘ軸と、ｙ軸の交点を点Ｏとする。そして、細管へ平行光束が入射する点を点ｌとし、点ｌの座標を（ｘ_１、ｙ_１）とする。そして、管壁を透過し、細管内側へ出射する点を点ｍとし、点ｍの座標を（ｘ_２、ｙ_２）とする。図３の（ｂ）は（ａ）の一部拡大図である。
【００２６】
図３に示されたように、平行光束（Ａ）は、点ｌで管壁に入射し、屈折して進み、点ｍで再屈折して、細管内に出射する軌跡をたどる。そこで、点ｌにおける入射角と、屈折角を求める。入射角をｉ_１、屈折角をｉ_１’とし、細管中心すなわち点Ｏと、点ｌのなす角をα_１、点Ｏと点ｍのなす角をα_２とすると、入射角ｉ_１は点Ｏと点ｌのなす角α_１に等しいから、入射角ｉ_１は数１によって与えられる。
【００２７】
【数１】

【００２８】
点ｌにおける屈折角ｉ_１’は数２によって与えられる。
【００２９】
【数２】

【００３０】
次に、点ｌの座標（ｘ_１，ｙ_１）は、数３及び数４のように表される。
【００３１】
【数３】

【００３２】
【数４】

【００３３】
点ｌから屈折して点ｍへ向かう軌跡、即ち点ｌと点ｍを結ぶ直線を、ｙ＝ａｘ＋ｂとすると、図３の（ｂ）から、傾きは、ａ＝ｔａｎ（ｉ_１−ｉ_１’）、切片は、ｂ＝ｙ_１−ａｘ_１となる。
【００３４】
点ｍは細管の内半径（Ｐ／２−ｔ）（但しｔは管壁の肉厚）の円と、前記ｙ＝ａｘ＋ｂとの交点であるから、点ｍの座標を（ｘ_２、ｙ_２）とすると、点ｍを通る円ｘ^２＋ｙ^２＝（Ｐ／２−ｔ）^２と、点ｍを通る直線ｙ＝ａｘ＋ｂを連立させてこれを解くと、数５、数６、数７が得られる。
【００３５】
【数５】

【００３６】
【数６】

【００３７】
【数７】

ここで、中心点Ｏと点ｍのなす角α_２は
【００３８】
【数８】

【００３９】
であるから、点ｍにおける入射角をｉ_２、屈折角をｉ_２’とすると、数９及び数１０のようになる。
【００４０】
【数９】

【００４１】
【数１０】

【００４２】
ここで、出射光束（Ｂ）は拡散光であるから、ｙ軸上に受光面を置いたとすると、出射光束（Ｂ）の軌跡がｙ軸と交わる点を求めることができる。この点ｍとｙ軸を結ぶ直線をｙ＝ｃｘ＋ｄとすると、図３の（ｂ）から、傾きｃは数１１
【００４３】
【数１１】

【００４４】
であり、ｙ軸との交点の座標は（０、ｄ）と表せ、したがって交点ｄは数１２、
【００４５】
【数１２】

【００４６】
によって求めることができる。この点ｄが、表１における出射光束（Ｃ）の受光半径を示すものである。
【００４７】
上記に示したような計算によって、前記表１は、外径３０ｍｍの細管について得られた結果であるが、図５は、さらに外径６０ｍｍ、及び１００ｍｍについて、算出して得られた計算データテーブルである。これによっても、細管の中央の位置での出射光束（Ｃ）に対する平行光束（Ａ）の比は１．０００となっており、細管の中央位置に受光面をおくことによって、平行光束と同じ断面積で受光することができることが了解される。また、前記した外径１４ｍｍや、外径１８ｍｍという円筒状インナーフィルタの透過率の測定も可能である。
【００４８】
次に、本発明の実施例２として、図４に管壁（６）を透過し、細管内へ出射された光の受光面の位置関係を示す。受光面（４）は前述したように細管中央位置（１２）に載置されるが、実施上、受光器は、狭い細管内に載置するには最小化に限度がある。そのため、光路途上に反射手段（３）を載置することによって、受光面（４）が虚像となる対象位置に第２の受光面（１５）を載置することができる。
【００４９】
図４に見るように、細管内壁と受光面との間に反射手段を置いた時に、反射手段（３）中心と受光面（４）の距離をａ、同じく反射手段（３）の中心と管壁（６）外側の距離をｂとすると、ａとｂの和は、円筒空間の外半径に等しく、この関係は第２の受光面（１５）位置においても同様である。細管の外半径をｒとすると、受光面の位置は、数１３で表わされる。
【００５０】
【数１３】

【００５１】
即ち、第２の受光面においても、入射する平行光束と同一の断面積において受光できることを示している。この結果、この細管中央部に受光面を載置することによって、細管の外径、肉厚の異なる細管でも測定が可能である。
【００５２】
【発明の効果】
本発明の方法は、上述した構成からなるので、正確な細管の透過率測定ができる効果を奏する。
【００５３】
すなわち、本発明の透過率測定方法によって、従来行えなかった測定困難な細管である円筒状フィルタの透過率測定を直接に測定できるという大きな効果が得られた。
【００５４】
本発明によれば、曲面を有する細管の透過率測定をフラットなフィルタの透過率測定値で代替することなく、細管内部に受光機能を入れて直接測定が可能となったことは、より正確な細管の透過率測定ができるという顕著な効果を有する。
【００５５】
さらに、本発明によれば、細管に入射する平行光束を、細管中心に受光面を置くことによって、細管での屈折、空気層での屈折に対する何ら補正手段を講ずることなく、容易に細管の透過率を測定できる効果を有する測定方法である。
【００５６】
また、本発明によれば、耐候光試験の途中におけるフィルタの経時変化を透過率の変化で確認する場合に、円筒状のフィルタ自体の測定をすることは不可能であったが、これを可能にした効果は非常に大きい。
【図面の簡単な説明】
【図１】本発明による実施例１における光束の位置関係を示す構成図である。
【図２】管壁を出射した光束が進む軌跡を示した図である。
【図３】入射平行光束の軌跡による光学的説明図である。
【図４】本発明の受光器の位置関係を示す図である。
【図５】外径６０ｍｍ、及び外径１００ｍｍについて各光束を算出した計算データテーブルである。
【図６】従来の透過率測定装置の構成図である。
【符号の説明】
１　細管
２　光源
３　反射手段
４　受光面
５　試料
６　管壁
７　受光器
８　光軸
９　平行光束（Ａ）
１０　出射光束（Ｂ）
１１　出射光束（Ｃ）
１２　細管中央位置
１３　拡散光
１４　透過率測定装置
１５　第２の受光面[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for measuring the transmittance of a light-transmitting optical cell, a filter surrounding a light-emitting portion of an artificial light source used in a weather resistance test device, and the like. More specifically, the present invention relates to a method for measuring the transmittance of a thin tube having a cylindrical shape of a cell or a filter.
[0002]
[Prior art]
Optical cells that have light transmittance and require transmittance measurement include optical cells used in spectral aging test devices and spectrophotometers. Is a prerequisite for measurement.
[0003]
As for the weather resistance tester, there is a filter surrounding the artificial light source. When the artificial light source is of a carbon arc lamp type, it may be a glass glove or a plate-like glass filter forming a lamp house for surrounding a pair of upper and lower carbons which emit and emit light by discharge. On the other hand, when the artificial light source is a long arc type xenon lamp, it is a cylindrical filter combining an inner tube for cooling an arc tube filled with xenon gas and an outer tube. A substantially similar filter is used for a metal halide lamp. The sample is irradiated with light transmitted through these gloves, glass filters, or cylindrical filters. The light from the lamp described above is required to have a spectral distribution of a rising wavelength according to the test object, and since there is also a change with time of the lamp and the filter, the transmittance of the filter is an important test factor. .
[0004]
In order to confirm the transmittance of the filter and the like, the transmittance is measured by a measuring device. Conventionally, as shown in FIG. 6, light from a light source is converted into a parallel light beam and applied to a plate-shaped sample to be measured, and transmitted light is received by a light receiver (integrating sphere) which is aligned with the light source and measured. . On the other hand, as an example of measuring the spectral transmittance of a sample having a curved surface, Japanese Patent Application Laid-Open No. H11-142241 discloses a configuration in which an integrating sphere is placed immediately after a test lens which is a sample. When the sample having a curved surface is a small tube with a small radius having a cylindrical shape as in the measurement object of the invention, the same configuration is impossible.
[0005]
That is, as the inner filter of the xenon lamp, a thin cylindrical filter having an outer diameter of 14 mm and an outer diameter of 18 mm has been practically used. The inside of the narrow tube is narrow, and a light source is provided on one side and a light receiving device is provided on the other side across the cylindrical tube wall. It is difficult to place the device in a straight line, and accurate light reception is not possible. Furthermore, even if a light source is placed on one side of the thin tube and a light receiver is placed on the other side, the light from the light source will be light that has been transmitted twice through the filter, i.e., twice through the tube wall. However, there is also a problem that light in the middle of the optical path is diffused so that it is impossible to accurately measure transmitted light.
[0006]
In general, parallel light from a light source is incident and refracted from a tube wall, refracted again when transmitted through a sample and emitted, and becomes diffused light. Also, when the light source is placed inside the cylinder and the light incident from the concave surface is emitted from the convex surface, the light is also diffused light. Japanese Patent Application Laid-Open No. 7-92020 discloses a radiation intensity measurement, in which a trajectory of light emitted from a luminous body and transmitted through an arc tube is not a parallel light beam. Various measurement methods are shown. Also in the measurement of the transmittance of a thin tube, it has been considered that it is difficult to receive an incident parallel light beam as a transmitted parallel light beam.
[0007]
Therefore, conventionally, the transmittance of a plate-shaped filter having the same material and the same thickness as the thin tube has been measured, and the measured value has been regarded as the transmittance of the thin tube. That is, the measurement of the thin tube itself has not been performed.
[0008]
Further, the change in the transmittance of the filter during the weathering light test must be measured on the filter itself, and it is of course impossible to substitute a plate filter.
[0009]
[Problems to be solved by the invention]
The present invention has been made in view of such a problem, and accordingly, an object of the present invention is to measure the transmittance of a thin tube in a cylindrical shape of a light-transmitting cell or filter by using a plate-shaped filter. It is an object of the present invention to provide a method of directly measuring the measurement object itself and obtaining the transmittance without substituting the transmittance with the transmittance.
[0010]
[Means for Solving the Problems]
In order to solve the above problems, the present inventors, based on trial and error, based on new knowledge obtained from optical considerations for the incident light beam to the measurement thin tube and the outgoing light beam emitted into the thin tube, The transmittance measurement method of the present invention was configured as follows.
That is, a light source is placed outside the thin tube, a light receiving surface is placed inside the thin tube, a parallel light beam from the light source is incident on the thin tube, and light emitted into the thin tube is received by the light receiving surface inside the thin tube. A transmittance measuring method, wherein an area of the light receiving surface is equal to a cross-sectional area of a parallel light beam.
[0011]
The light receiving surface is located at the center of the thin tube.
[0012]
Further, a reflecting means is provided between the inner wall of the thin tube from which the incident light beam is emitted and the light receiving surface, and the sum of the distance from the outer wall of the thin tube to the reflecting means and the distance from the reflecting means to the light receiving surface is equal to the outer radius of the thin tube. It is characterized by the following.
[0013]
According to the present invention, there is provided a measuring method capable of measuring the transmittance of a parallel light beam incident on the thin tube without taking any means for correcting refraction in the thin tube and refraction in the air layer.
[0014]
Further, since the positions of the reflection means and the light receiving surface in the thin tube can be specified, the transmittance can be measured regardless of the measurement site of the thin tube.
[0015]
【Example】
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In the transmittance measurement method of the present invention, a light source is placed outside the thin tube, a light receiving surface is placed inside the thin tube, and light from the light source is made to enter the thin tube as a parallel light flux, and light emitted through the tube wall. Is received by the light receiving surface. The area of the light receiving surface is equal to the cross-sectional area of the parallel light beam, and the light receiving surface is located at the center of the thin tube. Further, it is preferable that a reflecting means is placed between the thin tube and the light receiving surface, and that the sum of the distance from the reflecting means to the outer wall of the thin tube and the distance from the reflecting means to the light receiving surface is equal to the outer radius of the thin tube. It is. Further details will be described.
[0016]
FIG. 1 is a configuration diagram of Example 1 showing a transmittance measuring method according to the present invention.
In FIG. 1, light from a light source (not shown) placed outside the thin tube (1) is converted into a parallel light flux (9), which is incident on the thin tube (1), and light transmitted through the tube wall (6) is emitted into the thin tube. I do. The emitted light beam (10) is received by a light receiver (not shown) placed at a central position (12) in the thin tube.
[0017]
Here, the parallel light beam (9) incident on the thin tube (1) is (A), the outgoing light beam (10) out of the thin tube is (B), and the outgoing light beam (11) at the narrow tube center position (12) is ( C).
[0018]
As shown in FIG. 1, the emitted light beam (B) immediately after the emission is the diffused light (13). The parallel luminous flux (A) is refracted by the tube wall (6), advances so as to be converged, refracted and emitted again by the inner wall of the thin tube, and becomes diffused light. This is specifically shown in FIG.
[0019]
FIG. 2 shows how the emitted light beam (B) travels when the wall thickness (t) of the thin tube of 30 mm is 1.0 mm, 2.0 mm, and 5.0 mm by a trajectory. FIG. From this, regarding the measurement of the transmittance of the thin tube, new knowledge for stably measuring the diffused light has been obtained, and the present invention has been achieved. In the drawing, the optical axis (8) passing through the center of the thin tube of the parallel light beam (A) is defined as an x-axis, and a straight line perpendicular to the x-axis at the center of the thin tube is defined as the y-axis.
[0020]
That is, the light beam (B) emitted into the thin tube is refracted at the time of emission and is not parallel to the trajectory (shown by a broken line) extending the parallel light beam (A) parallel to the optical axis (8). Is shown in However, it can be seen that the emitted light beam (B) further advances and intersects a trajectory (broken line) extending the parallel light beam (A). Then, it is found that this intersecting point is plotted on the y-axis.
[0021]
When the diameter of the parallel light beam (A) is 5, 10, 15, and 20 mm, the diameters of the outgoing light beam (B) and the outgoing light beam (C) are calculated, and the outgoing light beam (B) and the outgoing light beam (C) are further calculated. ) Was calculated. Table 1 shows the results. The numbers are rounded to the fourth decimal place.
[0022]
[Table 1]

[0023]
That is, a new finding obtained by the present inventors is the ratio of the parallel light beam (A) to the output light beam (C) at the center position of the thin tube shown in Table 1. As can be seen from the table, the ratio of the parallel light beam (A) to the outgoing light beam (C) at the center position of the thin tube does not exceed 1. Therefore, the light intensity per unit area of the outgoing light flux (C) at the center position of the thin tube is equal to the light intensity per unit area of the incident parallel light flux (A), or with an error within 0.1%. It turned out to be. In particular, when the incident parallel light beam does not exceed a diameter of 5 mm, since the cross-sectional area of the output light beam (C) at the center of the thin tube and the parallel light beam (A) are equal, accurate transmittance measurement can be performed. I understand.
[0024]
From the measurement example using the conventional integrating sphere described above, when light transmitted through the tube wall (6) is received, it is assumed that light immediately after exiting to the concave surface of the thin tube is received. The ratio of the parallel light beam (A) to the emitted light beam (B) immediately after the emission is greater than 1. Therefore, when light is received at a position close to the tube wall, the intensity (density) of light per unit area is higher than that of the incident parallel light beam. From this, it is considered that it is preferable to set the light receiving surface at the narrow tube center position (12) for the parallel light beam (A).
[0025]
The optical considerations that led to the calculation data in Table 1 will now be described with reference to FIG. In FIG. 3A, the optical axis of the parallel light beam passing through the center of the thin tube is the x-axis, the axis passing through the center of the thin tube and perpendicular to the optical axis is the y-axis, and the intersection of the x-axis and the y-axis is Point O. The point at which the parallel light beam enters the thin tube is point l, and the coordinates of the point l are (x ₁ , y ₁ ). A point that transmits through the tube wall and exits to the inside of the thin tube is defined as a point m, and the coordinates of the point m are defined as (x ₂ , y ₂ ). FIG. 3B is a partially enlarged view of FIG.
[0026]
As shown in FIG. 3, the parallel light beam (A) enters the tube wall at the point l, refracts and proceeds, re-refracts at the point m, and follows the trajectory exiting into the thin tube. Therefore, the incident angle and the refraction angle at the point 1 are obtained. Assuming that the incident angle is i ₁ , the refraction angle is i _{1 ′} , the angle between the center of the thin tube, that is, the point O, and the point l is α ₁ , and the angle between the point O and the point m is α ₂ , the incident angle i ₁ is a point equal to the angle alpha ₁ of O and point l, the incidence angle i ₁ is given by the number 1.
[0027]
(Equation 1)

[0028]
The refraction angle i _{1 ′ at the} point l is given by Equation 2.
[0029]
(Equation 2)

[0030]
Next, the coordinates (x ₁ , y ₁ ) of the point 1 are expressed as in Equations 3 and 4.
[0031]
[Equation 3]

[0032]
(Equation 4)

[0033]
Assuming that a locus refracted from the point l and travels toward the point m, that is, a straight line connecting the point l and the point m is y = ax + b, the slope is a = tan (i ₁ −i _{1 ′} ) from FIG. ), The intercept is b = y ₁ −ax ₁ .
[0034]
Since the point m is the intersection of the circle of the inner radius (P / 2-t) (where t is the wall thickness of the tube) of the thin tube and the above-mentioned y = ax + b, the coordinates of the point m are represented by (x ₂ , y ₂ ), A circle x ² + y ² = (P / 2−t) ² passing through the point m and a straight line y = ax + b passing through the point m are solved simultaneously. can get.
[0035]
(Equation 5)

[0036]
(Equation 6)

[0037]
(Equation 7)

Here, the angle α ₂ between the center point O and the point m is
(Equation 8)

[0039]
Therefore, assuming that the incident angle at the point m is i ₂ and the refraction angle is i _{2 ′} , Equations 9 and 10 are obtained.
[0040]
(Equation 9)

[0041]
(Equation 10)

[0042]
Here, since the outgoing light beam (B) is diffuse light, assuming that the light receiving surface is placed on the y-axis, a point where the locus of the outgoing light beam (B) intersects the y-axis can be obtained. Assuming that a straight line connecting the point m and the y axis is y = cx + d, the slope c is given by the following equation (11) from FIG.
[0043]
[Equation 11]

[0044]
And the coordinates of the intersection with the y-axis can be expressed as (0, d).
[0045]
(Equation 12)

[0046]
Can be determined by: This point d indicates the light receiving radius of the emitted light beam (C) in Table 1.
[0047]
Table 1 shows the results obtained for the thin tube having an outer diameter of 30 mm by the calculation as described above. FIG. 5 shows the calculated data table obtained by further calculating the outer diameters of 60 mm and 100 mm. It is. Also in this case, the ratio of the parallel light beam (A) to the emitted light beam (C) at the center position of the thin tube is 1.000, and by placing the light receiving surface at the center position of the thin tube, the same break as the parallel light beam is obtained. It is understood that light can be received in an area. It is also possible to measure the transmittance of the cylindrical inner filter having an outer diameter of 14 mm or an outer diameter of 18 mm.
[0048]
Next, as Embodiment 2 of the present invention, FIG. 4 shows a positional relationship of a light receiving surface of light transmitted through the tube wall (6) and emitted into the thin tube. The light receiving surface (4) is placed at the center of the thin tube (12) as described above. However, in practice, the light receiver is limited to a minimum in order to be mounted in a narrow narrow tube. Therefore, by placing the reflection means (3) on the optical path, the second light receiving surface (15) can be placed at the target position where the light receiving surface (4) becomes a virtual image.
[0049]
As shown in FIG. 4, when the reflecting means is placed between the inner wall of the thin tube and the light receiving surface, the distance between the center of the reflecting means (3) and the light receiving surface (4) is a, and the center of the reflecting means (3) is also connected to the tube. Assuming that the distance outside the wall (6) is b, the sum of a and b is equal to the outer radius of the cylindrical space, and this relationship is the same at the position of the second light receiving surface (15). Assuming that the outer radius of the thin tube is r, the position of the light receiving surface is represented by Expression 13.
[0050]
(Equation 13)

[0051]
That is, it is shown that the second light receiving surface can also receive light with the same cross-sectional area as the incident parallel light beam. As a result, by placing the light receiving surface at the center of the thin tube, it is possible to measure even thin tubes having different outer diameters and wall thicknesses.
[0052]
【The invention's effect】
Since the method of the present invention has the above-described configuration, it has an effect that the transmittance of a thin tube can be accurately measured.
[0053]
That is, according to the transmittance measuring method of the present invention, a great effect was obtained in that the transmittance measurement of a cylindrical filter, which is a thin tube difficult to measure conventionally, could be directly measured.
[0054]
According to the present invention, the direct measurement is possible by inserting a light receiving function inside the thin tube without replacing the transmittance measurement of the thin tube having the curved surface with the transmittance measurement value of the flat filter. This has a remarkable effect that the transmittance of a thin tube can be measured.
[0055]
Further, according to the present invention, the parallel light beam incident on the thin tube can be easily transmitted through the thin tube without any correction means for refraction in the thin tube and refraction in the air layer by placing the light receiving surface at the center of the thin tube. This is a measuring method having the effect of measuring the rate.
[0056]
Further, according to the present invention, it is impossible to measure the cylindrical filter itself when checking the temporal change of the filter in the course of the weathering light test by the change in transmittance. The effect is very large.
[Brief description of the drawings]
FIG. 1 is a configuration diagram illustrating a positional relationship between light beams according to a first embodiment of the present invention.
FIG. 2 is a diagram showing a trajectory of a light beam emitted from a tube wall;
FIG. 3 is an optical explanatory diagram based on a trajectory of an incident parallel light beam.
FIG. 4 is a diagram showing a positional relationship of a photodetector of the present invention.
FIG. 5 is a calculation data table in which each light flux is calculated for an outer diameter of 60 mm and an outer diameter of 100 mm.
FIG. 6 is a configuration diagram of a conventional transmittance measuring device.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 thin tube 2 light source 3 reflecting means 4 light receiving surface 5 sample 6 tube wall 7 light receiver 8 optical axis 9 parallel light flux (A)
10 Outgoing light flux (B)
11 Emission light flux (C)
12 center position of thin tube 13 diffused light 14 transmittance measuring device 15 second light receiving surface

[0005]
In other words, the inner filter of the xenon lamp is a thin cylindrical filter that outer 14mm and an outer diameter 18mm is practically, a light source on one side of the capillary, even if measured at a light receiver on the other side, the light source From the filter, that is, light that has been transmitted twice through the tube wall, that is, there is a large amount of diffusion of light along the optical path to the light receiver, and there is a problem that accurate measurement of transmitted light cannot be performed. .

[0010]
[Means for Solving the Problems]
In order to solve the above problems, the present inventors, based on trial and error, based on new knowledge obtained from optical considerations for the incident light beam to the measurement thin tube and the outgoing light beam emitted into the thin tube, The transmittance measurement method of the present invention was configured as follows.

[0011]
That is, a light source is placed outside the thin tube, a light receiving surface is placed inside the thin tube, a parallel light beam from the light source is incident on the thin tube, and light emitted into the thin tube is received by the light receiving surface inside the thin tube. In a rate measuring method, the emitted light beam having a cross-sectional area equal to the cross-sectional area of the parallel light beam is measured at a position where the trajectory extending the parallel light beam and the emitted light beam intersect .

[0012]
Also, place the reflecting means between the capillary inner wall that incident light beam is emitted and the center position of the thin tube by reflecting the emitted light beam, the distance from the thin tube outer wall to said reflecting means, and from the reflecting means to the light-receiving surface The light receiving surface is placed at a position where the sum of the distances is equal to the outer radius of the thin tube.

[0015]
【Example】
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In the transmittance measurement method of the present invention, a light source is placed outside the thin tube, a light receiving surface is placed inside the thin tube, and light from the light source is made to enter the thin tube as a parallel light flux, and light emitted through the tube wall. Is received by the light receiving surface. Then , a reflecting means is placed between the inner wall of the thin tube and the center of the thin tube to reflect the emitted light beam , and the sum of the distance from the reflecting means to the outer wall of the thin tube and the distance from the reflecting means to the light receiving surface is equal to the outer radius of the thin tube. It is preferable that the light receiving surface is placed at an equal position, and the emitted light having a cross-sectional area equal to the cross-sectional area of the parallel light is measured . Further details will be described.

[0016]
FIG. 1 is a configuration diagram of Example 1 showing a transmittance measuring method according to the present invention.
In FIG. 1, light from a light source (not shown) placed outside the thin tube (1) is converted into a parallel light flux (9), which is incident on the thin tube (1), and light transmitted through the tube wall (6) is emitted into the thin tube. I do. The emitted light beam (10) is received by the photodetector (not shown) placed in the capillary.

[0024]
From the measurement example using the conventional integrating sphere described above, when light transmitted through the tube wall (6) is received, it is assumed that light immediately after exiting to the concave surface of the thin tube is received. The ratio of the parallel light beam (A) to the emitted light beam (B) immediately after the emission is greater than 1. Therefore, when light is received at a position close to the tube wall, the intensity (density) of light per unit area is higher than that of the incident parallel light beam. Therefore, the light receiving surface location Kukoto considered suitable to a position where the ratio of the parallel beam with respect to the emitted light beam (C) (A) does not exceed 1.

[0048]
Next, as an embodiment of the present invention, FIG. 4 shows a positional relationship of a light receiving surface of light transmitted through the tube wall (6) and emitted into the thin tube. As described above, the light receiving surface (4) in FIG. 4 is located at the central position (12) of the thin tube on the y-axis in optical considerations. However, in practice, the light receiver mounts the reflecting means (3) on the optical path. by location, it can be placed light receiving surface (15) to the target position to which the light receiving surface (4) is a virtual image.

[0049]
As shown in FIG. 4, when the reflecting means is placed between the inner wall of the thin tube and the center of the thin tube, the distance between the center of the reflecting means (3) and the center of the thin tube is a, and the center of the reflecting means (3) and the tube wall ( 6) When the outside of the distance and b, the sum of a and b is equal to the outer radius of the cylinder space, this relationship is the same in the light receiving surface (15) position. Assuming that the outer radius of the thin tube is r, the position of the light receiving surface (15) is expressed by Expression 13.

[0051]
That is, in the light receiving surface (15) show that it is possible to receive the emitted light beam of the same cross-sectional area parallel light beam incident. Further, by placing the light receiving surface at a position where the emitted light beam intersects with the trajectory of the extended parallel light beam , it is possible to measure even thin tubes having different outer diameters and wall thicknesses.

[0055]
Furthermore, according to the present invention, by arranging the light receiving surface at a position where the trajectory of the parallel light beam and the emitted light beam intersect , the parallel light beam incident on the thin tube is refracted by the thin tube and refracted by the air layer. This is a measuring method which has an effect of measuring as a luminous flux having the same cross-sectional area without taking any correction means , and easily measuring the transmittance of the thin tube.

[Brief description of the drawings]
FIG. 1 is a configuration diagram illustrating a positional relationship between light beams according to a first embodiment of the present invention.
FIG. 2 is a diagram showing a trajectory of a light beam emitted from a tube wall;
FIG. 3 is an optical explanatory diagram based on a trajectory of an incident parallel light beam.
FIG. 4 is a diagram showing a positional relationship of a photodetector of the present invention.
FIG. 5 is a calculation data table in which each light flux is calculated for an outer diameter of 60 mm and an outer diameter of 100 mm.
FIG. 6 is a configuration diagram of a conventional transmittance measuring device.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 thin tube 2 light source 3 reflecting means 4 light receiving surface 5 sample 6 tube wall 7 light receiver 8 optical axis 9 parallel light flux (A)
10 Outgoing light flux (B)
11 Emission light flux (C)
12 tubular center 13 diffuse light 14 transmittance measuring device 15 receiving light surface

[0011]
That is, a light source is placed outside the thin tube, a light receiving surface is placed inside the thin tube, a parallel light beam from the light source is incident on the thin tube, and light emitted into the thin tube is received by the light receiving surface inside the thin tube. In the rate measuring method, a cross-section area of the parallel light beam and a cross-sectional area of the output light beam are substantially equal at a position where the trajectory of the parallel light beam and the output light beam intersect , and the position is at the center of the thin tube. This is a new finding .

[0012]
In view of this, the means of the present invention reflects the emitted light beam by placing a reflecting means between the inner wall of the thin tube from which the incident light beam is emitted and the center position of the thin tube, and the distance from the outer wall of the thin tube to the reflecting means; The light receiving surface is placed at a position where the sum of the distances from the reflecting means to the light receiving surface is equal to the outer radius of the thin tube.

[0015]
【Example】
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In the transmittance measurement method of the present invention, a light source is placed outside the thin tube, a light receiving surface is placed inside the thin tube, and light from the light source is made to enter the thin tube as a parallel light flux, and light emitted through the tube wall. Is received by the light receiving surface. That is , a reflecting means is placed between the inner wall of the thin tube and the center of the thin tube to reflect the emitted light beam, and the sum of the distance from the reflecting means to the outer wall of the thin tube and the distance from the reflecting means to the light receiving surface is equal to the outer radius of the thin tube. It is preferable that the light receiving surface is placed at an equal position and the emitted light flux having a cross-sectional area substantially equal to the cross-sectional area of the parallel light flux is measured. Further details will be described.

[0047]
Table 1 shows the results obtained for the thin tube having an outer diameter of 30 mm by the calculation as described above. FIG. 5 shows the calculated data table obtained by further calculating the outer diameters of 60 mm and 100 mm. It is. Also in this case, the ratio of the parallel luminous flux (A) to the outgoing luminous flux (C) at the center position of the thin tube is 1.000. By placing the light receiving surface at the central position of the thin tube, it is almost the same as the parallel light beam. It is understood that light can be received in a cross-sectional area. It is also possible to measure the transmittance of the cylindrical inner filter having an outer diameter of 14 mm or an outer diameter of 18 mm.

[0051]
That is, it is shown that the outgoing light beam having the same cross-sectional area as the incident parallel light beam can be received on the light receiving surface (15) . Therefore, it is possible to measure even small tubes having different outer diameters and wall thicknesses.

[0055]
Furthermore, according to the present invention, the parallel light beam incident on the capillary, refraction at the capillary, without taking any correction means for refraction at the air layer, equality sectional area, measured as approximately equal emitted light beam, easily This is a measuring method having an effect that the transmittance of a thin tube can be measured.

Claims (3)

It relates to the measurement of the transmittance of an optical cell and / or an optical filter of a cylindrical thin tube. A light source is placed outside the thin tube, a light receiving surface is placed inside the thin tube, and a parallel light beam from the light source is incident on the thin tube. A light transmittance measuring method for receiving light emitted into a thin tube on a light receiving surface, wherein the area of the light receiving surface is equal to a cross-sectional area of a parallel light beam. 2. The transmittance measuring method according to claim 1, wherein the light receiving surface is located at the center of the thin tube. A reflecting means is provided between the inner wall of the thin tube and the light receiving surface, and the sum of the distance from the outer wall of the thin tube to the reflecting means and the distance from the reflecting means to the light receiving surface is equal to the outer radius of the thin tube. Item 4. The transmittance measurement method according to Item 1.

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