JP3470269B1 - Transmittance measurement method - Google Patents

Abstract

Abstract: PROBLEM TO BE SOLVED: To directly measure a measurement object itself without substituting the transmittance of a thin tube in a cylindrical shape of a cell or a filter having optical transparency with the transmittance of a plate filter. Providing a method for determining transmittance. SOLUTION: A light source is placed outside a thin tube, and a light receiving surface is placed inside the thin tube. Light from the light source is made into a parallel light beam (9) and made to enter the inside of the thin tube, and an emitted light beam emitted through a tube wall (9). 10)
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 narrow tube center position (12).

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a light transmitting property.
Optical cells and artificial light sources used in weather resistance test equipment
A method to measure the transmittance of a filter or the like surrounding the light emitting part
Related. More specifically, the shape of the cell or filter is cylindrical
The present invention relates to a method for measuring the transmittance of a thin tubular tube. [0002] 2. Description of the Related Art It has light transmittance and requires measurement of transmittance.
For example, spectrophotometers and spectrophotometers
There is an optical cell to be used,
Thus, the light transmission of the cell itself is a prerequisite for measurement. [0003] As for the weather resistance test apparatus,
There is a filter surrounding the artificial light source. Artificial light source is carb
In the case of the arc lamp type, the upper and lower carbon
A glass glove to surround the
This is a plate-shaped glass filter that forms a
Or On the other hand, if the artificial light source is a long arc type key
Xenon lamp filled with xenon gas
A circle combining an inner tube and an outer tube for cooling the arc tube
It is a cylindrical filter. Metal halide lamps are almost the same
Use a filter. These gloves and glass fills
The light that has passed through the filter or cylindrical filter
You. The light from the lamps described above
There is a demand for the spectral distribution of the rising wavelength.
Since the lamp and filter also change over time,
Is an important test factor. [0004] To confirm the permeability of this filter and the like.
Therefore, the transmittance is measured by a measuring instrument. Conventionally, in FIG.
As shown, the light from the light source is converted into a parallel
The transmitted light in a straight line with the light source
The light is received by the light receiving device (integrating sphere) in the above and measured. Against this
As an example of spectral transmittance measurement of a sample with a curved surface,
Japanese Unexamined Patent Publication No. Hei 11-142241 discloses a test lens
Configuration with an integrating sphere placed immediately after the
A sample having a curved surface, such as the measurement object of the invention, is cylindrical.
A similar configuration is not possible for small tubes with small radius.
You. That is, the above-mentioned xenon lamp inner
The filter is a thin circle with an outer diameter of 14 mm and an outer diameter of 18 mm
Cylindrical filters are in practical use,Light on one side of the tubule
Source and the receiver on the other side
Light from the source is transmitted through two filters, twice through the tube wall.
Light that has passed through the optical path, and
Difficult to measure transmitted light accurately
was there. In general, parallel light from a light source enters through a tube wall.
Refracts when it passes through the sample and exits.
Diffuse light. Also, put the light source inside the cylinder, and from the concave surface
When the incident light is emitted from the convex surface, the light is also diffused light.
Japanese Patent Application Laid-Open No. 7-92020 discloses radiation intensity measurement.
The light emitted from the illuminator moves through the arc tube.
Since the trace is not a parallel light beam, a supplementary correction for the measurement position is made.
A complex measurement method that provides a correct measure is shown. Tubule
In the transmittance measurement, the incident parallel light beam is
It was considered difficult to receive light as a bundle. Therefore, conventionally, the same material and the same thickness as the thin tube are used.
The transmittance of the filter was measured and measured.
The value has been taken as the capillary transmission. In other words, the tubule itself
No measurement has been performed. In addition, during the weathering light test,
Changes in transmittance must be measured on the filter itself
Of course, it is impossible to substitute a plate filter
It is. [0009] The present invention addresses such problems.
The present invention has been made in view of the
The purpose is to make cells or filters with optical transparency
Measurement of the transmittance of the capillary tube with the plate filter.
Measure the measurement target directly without substituting
Another object of the present invention is to provide a method for determining the transmittance. [0010] [MEANS FOR SOLVING THE PROBLEMS]
In addition, the present inventors, after trial and error,
Optics for incident light beam and outgoing light beam emitted into the thin tube
Of the present invention based on new findings obtained from
The rate measurement method was configured as follows. That is, the light source is placed outside the thin tube,
Place the light-receiving surface inside the tube and convert the parallel light flux from the light source into a thin tube.
Light incident on the tube and received by the light-receiving surface inside the tube
A transmittance measuring method, wherein the parallel light beam is extended.
At the position where the trajectory intersects the emitted light beam, the flat
The cross-sectional area of the line beam andThe cross-sectional areas of the emitted light beams are substantially equal,
It is a new finding that the position is at the center of the capillary. [0012]Therefore, the means of the present inventionIncident light beam exits
Reflecting means between the inner wall of the thin tube to be formed and the center position of the thin tube.
To reflect the emitted light beam, and to reflect the light beam from the outer wall of the thin tube.
And the distance from the reflecting means to the light receiving surface.
Place the light-receiving surface at a position where the sum of the separation is equal to the outer radius of the capillary.
And features. According to the present invention, a parallel light beam incident on a thin tube
To correct for refraction in the capillary and refraction in the air layer.
Measurement method that can measure the transmittance of a thin tube without taking steps
Is the law. Further, the position of the reflection means and the light receiving surface in the thin tube
The ability to identify the
This is a method that can measure excess ratio. [0015] BRIEF DESCRIPTION OF THE DRAWINGS FIG.
And will be described in detail. The transmittance measurement method of the present invention
Place the light source on the outside of the
The light from the tube is made into a parallel light beam, made to enter the narrow tube, and passed through the tube wall.
The emitted light is received by the light receiving surface.sand
WachiReflecting means between the inner wall of the capillary and the center of the capillary.
To reflect the emitted light beam from the reflection means to the outer wall of the thin tube
The sum of the distance of
Place the light receiving surface at a position equal to the outer radius of the
The cross section ofAlmostMeasuring the outgoing luminous flux of equal cross-sectional area
Is preferred. Further details will be described. FIG. 1 shows a transmittance measuring method according to the present invention.
1 is a configuration diagram of a first embodiment. In FIG. 1, a thin tube (1)
The light from the light source (not shown) placed outside the
(9), incident on the thin tube (1) and transmitted through the tube wall (6)
The emitted light exits into the thin tube. The emitted light beam (10)
Inside a small tubeToThe light is received by the placed light receiver (not shown). Here, a parallel light beam incident on the thin tube (1)
(9) (A), outgoing luminous flux (10) outgoing into the thin tube
(B), and the emitted light beam (11) at the capillary center position (12)
(C). As shown in FIG. 1, the emitted light immediately after the emission
Bundle (B) is diffused light (13). The parallel beam (A) is
Refracted at the tube wall (6), proceeded to converge, and at the inner wall of the capillary
The light is refracted and emitted again and becomes diffused light. This is specifically illustrated
It is shown in FIG. FIG. 2 shows a thin tube having an outer diameter of 30 mm.
Wall thickness (t) of 1.0 mm, 2.0 mm, and 5.0
mm, how the emitted light flux (B) proceeds.
It is the figure shown by the trace. From here, the measurement of the transmittance of the capillary
New information for stable measurement of diffused light
This is what led to the present invention. In the figure,
The optical axis (8) passing through the center of the thin tube of the row light beam (A) is the x-axis,
A straight line that intersects the center of the thin tube perpendicular to the x axis of
You. That is, the light beam (B) emitted into the thin tube is emitted.
A parallel light beam (A) that is refracted at the time of irradiation and is parallel to the optical axis (8)
Not parallel to the extended trajectory (indicated by the dashed line)
Is shown in the figure. However, the emitted light beam (B) further
Intersects a trajectory (broken line) that extends and advances the parallel light flux (A)
You can see that And this intersecting point is on the y-axis
To be plotted. Therefore, the diameter of the parallel light beam (A) is set to 5, 1
When the distance is 0, 15, and 20 mm, the emitted light flux (B) and the emitted light
Calculate each diameter of the light flux (C), and further calculate the output light flux (B) and
Calculate the ratio of parallel light flux (A) to outgoing light flux (C)
saw. Table 1 shows the results. The numbers are after the decimal point
The last 4 digits are rounded off. [0022] [Table 1] That is, the new findings obtained by the present inventors are shown in Table 1.
For the emitted light beam (C) at the center position of the thin tube shown in FIG.
Is the ratio of the parallel luminous flux (A). As you can see in the table
The parallel light flux (A) with respect to the output light flux (C) at the center position
The ratio should not exceed 1. Therefore, the center of the capillary
Light intensity per unit area of the emitted light beam (C) at the position
The degree is the light per unit area of the incident parallel light flux (A).
Equal to the strength or within 0.1% error
found. In particular, the incident parallel light beam should not exceed 5 mm in diameter.
In this case, the outgoing light beam (C) at the center of the capillary and the parallel light beam
Since the cross-sectional areas of (A) are equal, accurate transmittance
It turns out that measurement is possible. From the above-described measurement example using the conventional integrating sphere,
When receiving light transmitted through the tube wall (6),
Although it is assumed that the light immediately after being emitted to the
As shown in FIG. 1, the output light flux (B)
The ratio of the row luminous flux (A) is greater than one. Therefore, close to the tube wall
When light is received at the touching position, the light intensity per unit area
(Density) is higher than the incident parallel light beam
It has come out. From this,Outgoing light flux (C)
AgainstParallel light flux (A)Where the ratio of does not exceed 1Light reception
FacePlaceIt is considered preferable to use Then, the calculation data of Table 1 was obtained.
Optical considerations will be described with reference to FIG. In addition, FIG.
In (a), the optical axis of the parallel light beam passing through the center of the capillary is x
Axis, the axis passing through the center of the capillary and perpendicular to the optical axis is the y-axis,
The point of intersection of the x axis and the y axis is point O. And parallel to the capillary
The point where the light beam enters is point l, and the coordinates of point l are (x₁, Y
₁). Then, the light passes through the tube wall and exits to the inside of the thin tube.
Is a point m, and the coordinates of the point m are (x₂, Y₂).
FIG. 3B is a partially enlarged view of FIG. As shown in FIG. 3, the parallel light flux (A)
Is incident on the tube wall at point l, proceeds refracted, and re-refracted at point m
Then, the trajectory of emission into the thin tube is traced. So at point l
Angle of incidence and refraction angle. Incident angle i₁,refraction
The corner_{1 '}Between the center of the capillary, ie, point O, and point l
The angle is α₁, The angle between point O and point m is α₂Then the incident angle
i₁Is the angle α between point O and point l₁The incident angle i
₁Is given by Equation 1. [0027] (Equation 1) Refraction angle i at point l_{1 '}Is given by
Given. [0029] (Equation 2) Next, the coordinates (x₁, Y₁) Is the number 3
And Equation 4 [0031] (Equation 3) [0032] (Equation 4) A locus refracted from the point l toward the point m, that is,
Assuming that a straight line connecting the point 1 and the point m is y = ax + b, FIG.
From (b), the slope is a = tan (i₁−i_{1 '}), Off
The piece is b = y₁-Ax₁Becomes The point m is the inner radius of the capillary (P / 2-t) (where
t is the intersection of the circle with the wall thickness of the tube wall) and y = ax + b.
Therefore, the coordinates of the point m are (x₂, Y₂), The point m
Circle x passing through²+ Y²= (P / 2-t)²Pass through point m
Solving the straight line y = ax + b at the same time gives
6, Equation 7 is obtained. [0035] (Equation 5) [0036] (Equation 6) [0037] (Equation 7) Here, the angle α between the center point O and the point m₂Is [0038] (Equation 8) Therefore, the incident angle at the point m is i₂,
Refraction angle is i_{2 '}Then, as shown in Equations 9 and 10,
You. [0040] (Equation 9) [0041] (Equation 10) Here, is the outgoing light beam (B) a diffuse light?
If the light receiving surface is placed on the y-axis, the emitted light flux (B)
Can be obtained at the point where the trajectory intersects the y-axis. This point
Assuming that a straight line connecting the m and y axes is y = cx + d, FIG.
From (b), the slope c is [0043] [Equation 11] And the coordinates of the intersection with the y-axis are (0, d)
Therefore, the intersection d is [0045] (Equation 12) Can be obtained by This point d
Indicates the light receiving radius of the emitted light beam (C) in Table 1.
It is. By the above calculation, the above table is obtained.
1 is a result obtained for a thin tube having an outer diameter of 30 mm.
However, FIG. 5 further shows an outer diameter of 60 mm and an outer diameter of 100 mm.
And a calculation data table obtained by calculation. This
As a result, the output light flux (C) at the center of the capillary becomes
The ratio of the parallel light beam (A) to the light beam is 1.000,
By placing the light receiving surface in the center of the thin tube, the parallel light flux
WhenAlmostIt is understood that light can be received with the same cross-sectional area
It is. In addition, the above-mentioned outer diameter of 14 mm and outer diameter of 18 mm
It is also possible to measure the transmittance of the cylindrical inner filter.
You. Next, as an embodiment of the present invention, FIG.
(6) The position of the light receiving surface of the light transmitted through and emitted into the thin tube
Show the relationship.In FIG.The light receiving surface (4) is, as described above,
On the y-axis in optical considerationsAt the center of the thin tube (12)
However, in practice, the light receiver is provided with a reflecting means (3) on the optical path.
By placingTheA pair in which the light receiving surface (4) is a virtual image
In the elephant positionReceivingA light surface (15) can be placed. As can be seen in FIG.Tubule centerWhen
When the reflection means is placed between the center of the reflection means (3)Fine
Pipe center andIs the distance between a and the center of the reflecting means (3) and the tube.
Assuming that the distance outside the wall (6) is b, the sum of a and b is
Equal to the outer radius betweenReceivingOn the light surface (15)
It is the same as above. Assuming that the outer radius of the capillary is r,
surface(15)Is represented by Expression 13. [0050] (Equation 13) That is, the light is incident on the light receiving surface (15).
That it can receive an outgoing beam with the same cross-sectional area as a parallel beam.
Shows.Therefore, it is possible to use thin tubes with different outer diameters and wall thicknesses.
Can also be measured. [0052] The method of the present invention has the above-described structure.
Therefore, there is an effect that the transmittance of the thin tube can be accurately measured. That is, according to the transmittance measuring method of the present invention,
Therefore, a cylindrical tube, which is a thin tube difficult to measure
Great effect of directly measuring the transmittance of the filter
was gotten. According to the present invention, transmission of a thin tube having a curved surface
Replacing transmittance measurements with transmittance measurements on flat filters
Direct measurement possible by incorporating a light receiving function inside the thin tube without using
The result is that more accurate capillary transmittance measurement is possible.
It has a remarkable effect. Further, according to the present invention,,Incident on the tubule
What is the difference between parallel light flux and refraction in a capillary tube and air layer?
The cross-sectional areas are equal without taking any corrective measuresOr almost
equalMeasured as outgoing luminous flux to easily measure the transmittance of a thin tube
This is a measurement method having an effect that can be determined. Further, according to the present invention, during the weathering test,
Check the time-dependent change of the filter by the change in transmittance
Measurement of the cylindrical filter itself is not possible
Although it was effective, the effect that made this possible is very large.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram showing a positional relationship of a light beam according to a first embodiment of the present invention. FIG. 2 is a diagram illustrating 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. [Description of Signs] 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 beam (A) 10 Outgoing light beam (B) 11 Outgoing light beam (C) 12 Center position of thin tube 13 Diffusion light 14 transmittance measuring device 15 receiving light surface

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01M 21/00-21/01 G01M 21/17-21/61 G01M 11/00-11/08 G01N 21 / 84-21/958 PATOLIS

Claims (1)

(57) [Claims 1] The present invention relates to measurement of transmittance of an optical cell and / or an optical filter of a cylindrical thin tube used in a weathering test device, and a light source is mounted outside the thin tube. Then, a light receiving surface is placed in the thin tube, a parallel light flux passing through the center of the thin tube from the light source is incident on the thin tube, and a transmittance measurement method for receiving the emitted light beam emitted into the thin tube, comprising: And a reflecting means disposed between the inner wall of the thin tube to reflect the emitted light beam, 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 the outer radius of the thin tube. A light transmittance measuring method characterized in that a light receiving surface is placed at a position equal to the above.