JPH04138326A - Photometric apparatus - Google Patents

Abstract

PURPOSE:To simplify the connecting operation between a sample and the main body of an apparatus by splitting light which is cast into one end of an optical fiber and light which is emitted from the same end by using a semitransparent mirror, and guiding the light from the sample into a photometric part. CONSTITUTION:Monochromatic luminous flux F emitted from a spectroscope 1 is reflected from a semitransparent mirror 3 and cast into a sample S through an optical fiber 2 and a jig 5. Then, the luminous flux which is reflected from the sample S is measured with a light measuring part 4 through the optical fiber 2 and the semitransparent mirror 3. A part of the luminous flux F emitted from the spectroscope 1 is transmitted through the semitransparent mirror 3 and received with a photodetector 6. Thus, the change in outgoing light from the sample is monitored.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a photometric device such as a spectrophotometer or a colorimeter using an optical fiber.

(Conventional technology) Spectrophotometers using optical fibers can freely set the position of the sample relative to the spectrophotometer body, so they are not subject to restrictions such as the size and shape of the sample, and whether the sample is liquid or solid. There are no advantages.

Conventional spectrophotometers of this type have either a type in which the sample irradiation optical fiber and a light receiving fiber are independent, or a branched type in which the sample side ends of the illuminating optical fiber and the light receiving fiber are combined into one bundle. It uses optical fiber.

However, in the above-mentioned type in which both the light emitting and receiving optical fibers are independent, high precision is required for mutual position adjustment of the respective sample side end faces, and in the type in which the sample side ends of both optical fibers are bundled together, effective light reception is difficult. There was a drawback that the surface could not be removed sufficiently.

(Problems to be Solved by the Invention) The present invention seeks to provide a spectrophotometer that eliminates the disadvantages of the two types of conventional spectrophotometers using optical fibers described above.

(Means for solving the problem) Inject sample illumination light from one end of the optical fiber, project the light emitted from the other end onto the sample, and - Inject the light reflected or transmitted from the sample from the other end of the optical fiber. Let me,
The light was emitted from the one end, and the light incident on the one end of the upper optical fiber was separated from the light emitted from the same end using a semi-transparent mirror, so that the light from the sample was guided to the photometry section.

(Function) According to the present invention, the light for illuminating the sample and the light from the sample pass through the same optical fiber in opposite directions. The sample illumination light is emitted from one optical fiber, and the light from the sample is incident on that optical fiber, so both the illumination and sample light are emitted and received from the same place, which makes it difficult to use two independent fibers. This eliminates the need for mutual positional adjustment of one end of the two fibers. In addition, in a case where separate optical fibers for illumination and light reception are combined into a bundle at the end of the sample bundle, if the cross-sectional area of each optical fiber is the same, out of the light from the sample that enters the entire end of the sample side. Only half of the light can enter the receiving optical fiber, but since the present invention uses the same optical fiber for illumination and light receiving, all the light from the sample that has entered the entire area of one end of the optical fiber can travel back through the optical fiber, resulting in effective light reception. This means that the area has been doubled. This advantage can be offset by using a semi-transparent mirror, but the ratio of the reflectance and transmittance of the semi-transparent mirror can be changed (transmittance or reflectance) on the side where the light from the sample goes to the photodetector. This problem can be solved to some extent by making it large. For example, when light from a sample is reflected by a semi-transparent mirror and guided to a light receiving element, the reflectance of the semi-transparent mirror is 75%.
If the transmittance is 25%, then 75% of the light from the sample can be received.

(Example) FIG. 1 shows an example of the present invention. In the figure, reference numeral 1 indicates a monochromatic light beam emitted from a spectrometer F, reference numeral 2 indicates an optical fiber, and reference numeral 3 indicates a semi-transparent mirror. The semi-transparent mirror 3 reflects the spectrometer output light flux F toward one end of the optical fiber 2, and transmits the light emitted from the same end face of the optical fiber 2 to the photometry section 4. A suitable jig is attached to the other end of the optical fiber 2 depending on the purpose of measurement. The embodiment shown in FIG. 1 shows the case of measuring the light transmittance of a liquid, in which the jig 5 has a notch 51 and is inserted into the sample solution in the container 7, and the side end of the optical fiber is inserted into the notch. is located, and a lens 52 whose convex surface is a mirror is located on the opposite surface.
The light emitted from the end face of the optical fiber travels back and forth within the notch and enters the same end face. At this time, the lens 52 functions as a condensing mirror. This embodiment has the configuration of a single-beam spectrophotometer, and utilizes the fact that a part of the sample illumination light flux F incident on the semi-transparent mirror 3 is transmitted through the semi-transparent mirror 3. It is designed to receive light and monitor changes in the sample irradiation light.

FIG. 2 shows another example of a jig attached to the end of the optical fiber 2 on the sample side. 2A is a jig for measuring absorbance using the ATR method, B is a jig for measuring reflectance using an integrating sphere, and S is a sample.

(Effects of the Invention) According to the present invention, since a common optical fiber is used for illuminating the sample and for receiving light, the apparatus can be made at a lower cost than using two optical fibers, and the position adjustment of the optical fiber on the sample side can be performed in two steps. It is easier to use than a book optical fiber with separate ends on the sample side, improves the reproducibility of measurement results, and requires only one optical fiber, so the connection between the sample and the main body of the device, such as a spectrophotometer, is easier. Connection operations between the two become easier.

[Brief explanation of drawings]

Fig. 1 is an overall view of an apparatus according to an embodiment of the present invention, Fig. 2A is a side view of another embodiment of the measuring jig, and Fig. 2B is a side view of yet another jig. . DESCRIPTION OF SYMBOLS 1... Spectrometer, 2... Optical fiber, 3... Semi-transparent mirror, 4... Photometry part, 5... Measurement jig, 6...
Light receiving element for monitor. Agent Patent Attorney Hiroshi Agata 1st Figure hlv Q-1'C) Condolences.

Claims (1)

[Claims] Specimen illumination light is input from one end of the optical fiber, the light emitted from the other end is projected onto the sample, the light reflected or transmitted from the sample is input from the other end of the optical fiber, and the light is emitted from the one end; A photometric device characterized in that the light incident on the one end of the optical fiber and the light emitted from the same end are separated using a semi-transparent mirror, and the light from the sample is guided to the photometric section.