JPS6195220A - Spectrophotometer - Google Patents

Abstract

PURPOSE:To enable the measurement of a specimen which can not be measured in a spectrophotometer, by providing a separate specimen chamber other than a spectrophotometer and connecting this separate specimen chamber and the specimen chamber of the spectrophotometer by an optical conduit to introduce specimen light into the separate specimen chamber. CONSTITUTION:A separate specimen chamber 24 is provided apart from a spectrophotometer 22. This separate specimen chamber 24 is connected to the specimen chamber 14 of the spectrophotometer 22 by optical conduits 20, 36 such as optical fibers. A specimen 32 is received in the separate specimen chamber 24 and specimen light 10 is incident to the separate specimen chamber 24 from the spectrophotometer 22 by the optical conduit 20 while light after transmitted through the specimen 32 is again returned to the spectrophotometer 22 by the optical conduit 36 to perform necessary data processing in the spectrophotometer 22. By this method, even with respect to a specimen incapable of being measured in the spectrophotometer 22 like a radioactive specimen, measurement can be performed in the same way as a usual specimen.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a spectrophotometer capable of measuring large samples or hazardous substances.

[Background of the invention]

A conventional device, as described in Japanese Patent Application Laid-Open No. 57-175246, has a cell holder and a detector arranged in a removable unit, and a sample beam and a reference beam detached from a light source and a monochromator unit by means of a light conduit. The sample cell and the reference cell are configured to be guided into the sample holder of the possible unit.

When measuring radioactive samples using such conventional equipment,
Since the detection part and the cell part are close to each other, there is a high risk that the detection part will be exposed to radiation, making it unsuitable for measuring radioactive substances.

[Purpose of the invention]

An object of the present invention is to provide a spectrophotometer that can measure samples that cannot be measured within the sample chamber of the spectrophotometer.

[Summary of the invention]

In order to achieve the above object, the present invention guides light separated by a spectrometer of a spectrophotometer from a sample chamber to a separate sample chamber installed outside the spectrophotometer using a lead tube, and The light after passing through the sample is guided into the sample chamber of the spectrophotometer, and a detector installed in the spectrophotometer converts the optical signal into an electrical signal and performs data processing.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be briefly described with reference to the drawings.

In FIG. 1, white light emitted from a light source is converted into monochromatic light by a spectroscope, divided into sample light 10 and reference light 12 by a chopping mechanism, and guided to a sample chamber 14. Sample light 1
0 is about 5m wide and 8 high! The light beam I11 is converged into a spot about 2 fins wide and 4 fins high at the incident end face 2OA of the optical fiber 20 via the lens 16 and mirror 18.
A single fiber is irradiated. The sample light 10 is guided by the optical fiber 20 to a separate sample chamber 24 independent of the spectrophotometer 22 and is emitted therefrom, but the light beam from the optical fiber 20 has a spread pattern based on total reflection as the transmission principle. For this reason, an optical element 26 is installed near the output end face 20B of the optical fiber 20 to convert the light into parallel rays.

The parallel light edge 30 is irradiated onto the sample 32, and the light beam is converged by the light collecting element 34 to form a spot of approximately φ3B and irradiated onto the incident end surface 36A of the optical fiber 36. optical fiber 36
The irradiated light is guided again to the sample chamber 14 of the spectrophotometer 22, and is passed from the output end 36B of the optical fiber 36 to the similar mirror 42.
The light energy is irradiated onto the detection section of the spectrophotometer 22 through the lens 44, and the light energy is converted into an electrical signal, and the signal is displayed on the display section in the data processing section and recorded on a printer or the like.

On the other hand, the contrast light 12 is collected by the lens 46 and the slit 4
At step 8, the sample light 10 is balanced and irradiated to the detection section of the spectrophotometer 22 through the lens 50.

This control light 12 can be guided to a separate sample chamber in exactly the same manner as the sample light 10, if necessary, and can easily be balanced with the sample light 10.

With this configuration, the dimensions of the separate sample chamber 24 can be changed freely as necessary.

In addition, the length of the optical fiber was changed and the spectrophotometer 2 was placed in a separate room.
2. Measurement of dangerous substances by remote control is also possible.

FIGS. 2 to 4 show an embodiment in which a glass holder for measuring large glass is installed in a separate sample chamber.

52 is a metal tube leading the end face of Hikari 7 Eyeper 20,
It is supported by a tube 56 attached to the case 54, and the output position of the optical fiber 20 is also adjusted by this metal tube 5.
This can be done by changing the fixed position of 2. 60 is a screw for fixing the metal tube 52 by tightening the tube 56 in the boss 58, and 62 is a supporter that supports the large glass 64 by sandwiching it with a spring 66. The spring 66 is bendable and its position can be varied depending on the thickness of the large glass 64. 68 is a mechanism for moving the large glass 64t vertically and horizontally, the details of which are shown in FIG.

It is shown in Figure 4. A cover 70 is fixed to the case 54 with metal fittings 72 so that it can be opened and closed.

In FIGS. 3 and 4, reference numeral 74 denotes a rail for moving left and right a base 78 on which a large glass 64 is set, and has a fixing mechanism 80 so that it can be fixed at any desired position to be measured. 82
is a base on which the rail 74, roller mechanism 84, and nut mechanism 86 are attached, and by rotating the handle 88, the feed screw 90
By rotating the nut mechanism 86, the nut mechanism 86 moves up and down, and the base 82 connected to the nut mechanism 86 moves up and down. The roller mechanism 84 rotates on the rail 92 as the base 82 moves up and down. Reference numeral 94 denotes a bearing for the feed screw 90, which has bearings 96 on both sides to ensure smooth rotation. Reference numeral 90 represents the entire base, and reference numeral 100 represents a supporter for supporting the V-ru 92, which is fixed to the shingle base 98 with screws 102.

With this configuration, even for large glasses that cannot be set in the spectrophotometer sample chamber, transmittance measurements can be made freely at any position in the external sample chamber.

Other examples are shown in FIGS. 5 to 9.

FIG. 5 shows an embodiment in which a 70-cell 110 is set in a separate sample chamber 24 placed in a separate room far away from the spectrophotometer in order to measure dangerous samples such as radioactive substances. Further, an optical element 26 placed near the output end of the optical fiber 20 and converting the light into parallel light edges is fixed within the metal tube 52 .

FIG. 6 shows an embodiment in which a waste cell 112 is set in an external sample chamber 24, where 114 is a cell stand and 116 is a light-shielding lid.

It is also easy to set the flow cell set of FIG. 5 on the sample side and the 6th direction cell set on the control side, using the optical fiber 20 from the spectrophotometer in the separate sample chamber 24. father,
The flow cell set shown in FIG. 5 and the corner cell set shown in FIG. 6 can also be used separately.

FIG. 7 shows the support fitting 1 for measuring the total diffuse reflection of the sample 118.
20 is set in the external sample chamber 24, and an example is shown in which the original input fiber 122 and the output optical fiber 124 are coaxial.

FIG. 8 shows an example in which the relative reflectance of specularly reflected light from a sample 130 is measured using mirrors 126 and 128. When performing 1001% correction, it is sufficient to place a reference mirror or a reference sample at the same position as the sample 130 by 7'1.

- FIG. 9 shows an example of measuring the absolute reflectance of specularly reflected light of a sample 132, in which reference numerals 134 and 136 are mirrors, and 138 is a reference mirror. When correcting 100m, the solid line optical system, that is, the incident light is mirror 134, reference mirror 138, and mirror 13.
6, the light is irradiated onto a light collecting element 34 attached to the incident end face of an optical fiber 36. When measuring the sample 132, the sample 132 is set at position P, the reference mirror 138 is set at position P2, and the mirror 136 is switched as shown by the dotted line.

As shown in Figures 2 to 9, by setting the attached equipment according to the size of the sample to be measured and the contents of the measurement in a place other than the sample chamber of the spectrometer, the size of the sample chamber can be Rather than determining the size of the sample according to the size, measurements can be made at the actual size of the sample. Therefore, it is possible to control the quality of the production line, for example, to measure the transmittance of window glass.

It is also excellent from a safety point of view, as measurements of changes in the transmittance of glass filters and the like over time, such as how they change when irradiated with radiation, can be carried out from a distance (using a spectrophotometer).

The most important point in locating a separate sample chamber is the technology to guide the light separated by the spectrophotometer to the detector without loss.

Optical transmission loss due to optical fibers includes surface reflection loss at the input end face, absorption loss due to the core material, loss due to internal bubbles in the core material and scattering due to foreign objects, bending loss due to fiber bending, and surface reflection loss at the output end face. , and there is a loss from the spread of the light emitted from the output end of the optical fiber due to the space in the specimen portion until it enters the next optical fiber. Among the individual losses mentioned above, the loss that is particularly large compared to the others is the loss up to the input end of the final optical fiber.

Actual measurement data ``t'' of this loss is shown in Fig. 1θ. As the distance t between the seven optical eyes increases, the loss increases rapidly.

This is caused by the spread 9 of the optical fiber output light and the incident angle θ of the light that can be transmitted by the optical fiber i-, as shown in FIG. In general, for optical fibers, the maximum angle at which total reflection occurs, that is, the acceptance angle, is determined by the numerical aperture (Numerical Aperture).
Aperture) NA is called formula (1)% formula% where nl: refractive index of core 180 n2: refractive index of crut 182 The incident angle at this time is the maximum angle, and light at angles larger than this will propagate within the fiber. This will result in a loss. Since the field fNA of the quartz fiber is 0.21 and θ is 12°, only light within 2θ=24° is transmitted. In order to reduce these losses as much as possible, it is necessary to devise the end face of the optical fiber and make the light emitted from the optical fiber a parallel beam, as shown in FIGS. 12 to 14.

As shown in FIG. 1, the sample light lO separated by the spectrophotometer 22 has a width of about 2 m at the incident end face 20A of the optical fiber 20.
, are converged into a spot with a height of 4 mm. In order to effectively make this light enter the input end face 20A of the optical fiber 200, the shape of the light receiving part 184 is approximately 3 m wide and approximately 5 m high, as shown in Figs.
Match the shape 186 of 0B with the sample transmission window diameter 4 steel φ to approximately 3Wφ
A lens 188 with a long focal length is installed at the output end to form an approximate parallel beam 190.

End face 1 of the optical fiber 36 that receives the light transmitted through the sample
The dimension of 92 is 5mφ, which is slightly larger than the sample transmission window diameter of 4mmφ.
And so. The shape 194 of the output end of the optical fiber 36 is approximately 3
The sample φ was transmitted to a spectrophotometer via a mirror 42. This reduced the optical loss to 1150, reduced the total noise by 1/10, and enabled stable measurements.

〔Effect of the invention〕

According to the present invention, there is an effect that there is no restriction on the size of the sample, and dangerous substances such as radiation can be measured by remote control.

[Brief explanation of drawings]

Fig. 1 is a diagram of the number of grooves of the spectrophotometer according to the present invention, Fig. 2 is a side view of a glass holder for measuring large glass, and Fig. 3 is a diagram of the number of grooves of a spectrophotometer according to the present invention.
Figure 4 is a front view of Figure 2, Figures 5 to 9 are
The figures show another example of the sample chamber, Fig. 10 shows the relationship between the distance between optical fibers and the output, Fig. 11 shows the optical transmission loss of the optical fiber, and Figs. 1
Figure 4 is a detailed diagram of the optical fiber. 10... Sample light, 12... Control light, 14.24...
・Sample chamber, 20.36...Optical fiber, 22...
Spectrophotometer, 32...sample.

Claims (1)

[Claims] 1. The light separated by the spectrometer of the spectrophotometer is guided from the sample chamber to another sample chamber installed outside the spectrophotometer using a lead tube, and the light after passing through the sample in the separate sample chamber is A spectrophotometer, characterized in that the spectrophotometer is guided into a sample chamber of the spectrophotometer, and a detector installed in the spectrophotometer converts an optical signal into an electrical signal and performs data processing.