JPH02198339A - Variable-angle spectroscopic measuring apparatus - Google Patents

Abstract

PURPOSE:To perform various kinds of measurements with one apparatus by providing a light measuring device on the extending line of the incident luminous flux into a specimen so that the device can be replaced in addition to photodetectors which are attached on a detecting stage. CONSTITUTION:Either of photodetector 3 or 4 is selected. A detecting stage 2 is rotated. The photodetector is positioned on the extending line of an optical axis A on the side of the transmitting side of a specimen. The relationship between a rotary angle theta and the output of the photodetector at this position is obtained. When the opacity of the similar specimen is measured, the detecting stage 2 is turned so that both photodetectors 3 and 4 are deviated from the optical axis A and so that the light transmitted through the specimen is inputted into an integrating sphere 7. Then, the specimen is provided on the light inputting window of the integrating sphere 7 with a specimen holder 91 that is provided at a holding stage 9. A photodetector 8 is selected with a detector-switch selecting mechanism 12. Thus the light transmitted through the specimen is measured. A light emitting window 71 at the rear side of the integrating sphere 7 is opened, and the opacity is measured. Then, the light obtained by subtracting the direct transmitted light from the light transmitted through the specimen is measured. When the window 71 is covered with a white plate, the total transmitted light including the diffused light and the direct transmitted light can be measured. The difference between both measured values is divided by the later measured value, and the clouding degree is obtained.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a variable angle spectrometer used to measure the spectral transmittance or spectral reflectance of a sample by changing the angle between the sample surface and the human output light. Regarding.

(Prior Art) A conventional variable angle spectrometer has a structure as shown in FIG. In this figure, reference numeral 1 denotes a sample stage that can be rotated around the 0 point by an axis perpendicular to the paper surface of the figure, and a sample S is placed on this stage. Reference numeral 2 denotes a detector stand, which is rotatable about the 0 point coaxially with the sample stand 1 and independently of the sample stand, and has a fixed photodetector. A is the optical axis of the spectrometer, which is perpendicular to the rotation axis of the sample stage 1, and monochromatic light emitted from a light source device consisting of a lamp and a spectrometer (not shown) is incident on the sample S along this axis. It will be done. With this configuration, the angle of incidence of the measurement light on the sample can be changed arbitrarily, and by surrounding the detector stand 2, the light reflected or transmitted (scattered) from the sample in any direction can be reflected or transmitted (scattered) by the detector. Can be detected and measured.

(Problem A to be Solved by the Invention) The conventional variable angle spectrometer described above has one photodetector mounted on a rotary table, and therefore has the following inconveniences.

First, because the detector is mounted on a rotary table, it is difficult to use large photometers, such as those that use an integrating sphere. For measurements that do not have a simple shape, such as when measuring a sample in which the transmitted light beam and the reflected light beam diverge, such as a lens, a separate device must be used. Also, since there is only one detector, three-beam measurement is not possible.

Therefore, the present invention aims to provide a highly versatile variable-angle spectrometer that is capable of both measurements using a large photometer and measurements using the three-beam method.

(Means for solving the problem) A sample stage rotatable around an axis perpendicular to the optical axis of an incident light beam, a detector stage rotatable coaxially with the sample stage and independently of the sample stage, A variable angle spectrometer comprising a light detection means mounted on the detector stage and a replaceable photometry means arranged on the rear extension of the intersection of the optical axis of the incident light beam with the center line of the sample stage. provide.

(Example) FIG. 1 and FIG. 2 show an embodiment of the device of the present invention.

In the figure, 1 is a sample stage and 2 is a detector stage, both of which can rotate independently of each other around an axis that passes through the 0 point and is perpendicular to the plane of the figure. separated by an angle θ N:
Two photodetectors 3.4 are installed. Of these two photodetectors, one 3 is a photomultiplier tube and the other 4 is a PbS element, and 3 is used for measurements in the short wavelength range, and 4 is used for measurements in the long wavelength range. It is possible to switch and select electrically. Reference numerals 5 and 6 are motors that drive the sample stage and the detector stage. A is the optical axis of the light flux incident on the sample, and on the right side of the figure is a light source device consisting of a spectrometer and a lamp. 7 is a small-diameter integrating sphere arranged on an extension of the optical axis A past the center line O. A photodetector 8 detects the light emitted from the integrating sphere 7. 9 is a stand holding the integrating sphere 7 and a positioning bin 10
It is positioned on the device base and fixed with a fixing screw 11, and by removing this screw, the integrating sphere 7 can be removed and another measuring device can be installed in the place where the small diameter integrating sphere 7 remains. can. Reference numeral 12 denotes a photodetector switching and selection mechanism which electrically selects photodetectors such as 3°, 4°8, etc. using a switch.

FIG. 3 shows another measuring device that can replace the small-diameter integrating sphere 7, in this example a large-diameter integrating sphere 13, which is mounted on a holder 14 of the same dimensions as the holder 9 of the small-diameter integrating sphere 7. ,
The positioning pin 10 of the stand 14 and the hole 15.16 that fits the fixing screw 11 allow it to be positioned and fixed at the location where the holding stand 9 was removed.

In FIGS. 1 and 2, a sample holder 17 clamps and fixes the sample S on the sample stage 1.

Some measurement aspects in the above-mentioned apparatus will be explained. In the case of measuring the angle dependence of scattered and transmitted light of a light-scattering sample, the sample is adjusted to a parallel plane plate, held by the sample holder 17 as shown in FIG. 1, and one of the photodetectors 3.4 is selected. However, the detector stage 2 may be rotated to position the photodetector on the extension of the optical axis A on the sample transmission side, and the relationship between the rotation angle φ from that position and the photodetector output may be determined. When measuring the haze of a similar sample, rotate the detector stand 2 to remove both of the photodetectors 3 and 4 from the optical axis A so that the light transmitted through the sample is incident on the integrating sphere 7. A sample holder 91 attached to a holding table 9 is installed at the light entrance window of the integrating sphere 7, a photodetector 8 is selected by the detector switching selection mechanism 12, and the sample transmitted light is measured. Cloudiness is the ratio of the directly transmitted light to the total transmitted light of the sample. When photometry is performed with the light exit window 71 at the back of the integrating sphere 7 open, the amount of light transmitted through the sample excluding the directly transmitted light is measured. If the window 71 is covered with a white board, the total light transmitted through the sample, including the diffused light and the directly transmitted light, can be measured, so the cloudiness can be determined by dividing the difference between the constant values on both sides by the subsequent measured value. Needless to say, it is also possible to measure the relationship between the angle of incidence and the angle of reflection of light reflected from the sample surface. By performing the above measurements while changing the wavelength, each spectral characteristic can be determined. When priority is given to sensitivity in measurements using an integrating sphere, a small-diameter integrating sphere 7 is used, and when emphasis is placed on the integrating sphere effect, a large-diameter integrating sphere with a small ratio of window area to sphere inner surface precision is used. As shown in FIG. 1, the integrating sphere can also be used for measurement using the three-beam method by making reference light incident thereon.

(Effects of the Invention) According to the present invention, in addition to the photodetector mounted on the detector stand, the photometric device is replaceably arranged on the optical axis extension of the light flux incident on the sample. The device made it possible to perform a wide variety of measurements.

[Brief explanation of the drawing]

Fig. 1 is a plan view of an embodiment of the present invention, Fig. 2 is a side view, Fig. 3 is a plan view of another photometric device used in the same embodiment, and Fig. 4 is a schematic plan view of a conventional device. be. 1... Sample stand, 2... Detector stand, 3.4... Photodetector, 5, 6... Drive motor, 7... Small diameter integrating sphere,
8... Photodetector, 9... Integrating sphere holding stand, 12...
Photodetector switching selection mechanism, 13...Large diameter integrating sphere. Agent: Hiroshi Agata, Patent Attorney, Figure 2

Claims (1)

[Claims] A sample stage rotatable around an axis perpendicular to the optical axis of the incident light beam, a detector stage rotatable coaxially with the sample stage and independently of the sample stage, and a detector stage mounted on the detector stage. A variable-angle spectrometer comprising: a photodetector; and a replaceable photometer disposed on the rear extension of the intersection of the optical axis of the incident light beam with the center line of the sample stage.