JPH0829345A - Measuring device that guides a light beam through a liquid medium - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a measuring device that guides a light beam through a liquid medium and completely or partially receives the light beam again, and in particular, performs spectroscopic analysis. A measuring device (1) for performing an optical measurement or a spectroscopic analysis at a greater distance from a measuring device (2) has two parallel light guides, one of which is a light guide. , Another light guide returns the light guided through or scattered by the medium to the meter for analysis. In this case, the measuring path (8) or measuring chamber (15) is in front of the mouth of one light guide, that is to say a light guide that emits or, preferably, a light guide (3) that receives light. That is, the light deflector is adjacent to the original measuring path and is not divided by the measuring path. The external dimensions of the cross section of the measuring device (1) can be correspondingly reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring device for guiding a luminous flux through a liquid medium and receiving the luminous flux completely or partially again, and in particular to a spectroscopic analysis. Has two light guides that are essentially parallel, and at the end of said light guide reflects light by a mirror or prism to direct light from the mouth of one light guide to the mouth of another light guide. The present invention relates to a type in which a measuring path is provided between the optical conductor portions, which is deflected, a test medium is introduced into the measuring path, and a light flux passes through the medium.

[0002]

2. Description of the Related Art Measuring devices of this kind are already known. In fact, in the case of the known solution, a 45 ° mirror is provided at the end of the light-conducting light guide, and a medium introduction slit is provided adjacent to said mirror, on the other side: A second mirror, also at 45 °, transmits the second light that is transmitted and passes through an inlet that serves as a measurement path between the mirrors.
It serves to feed the light guide and to reflect it parallel to the light emerging from the end of said light guide. That is, the light flux can pass through the liquid medium between the two deflections of the mirror, so that again the received light flux can be analyzed correspondingly. For this purpose, both mirrors have to be made very precisely, in particular also so precisely mounted, that the incident light is effectively received again after passing through the medium and is incident on the second light guide. In this case, the dimension of the medium introduction slit, which serves as a measuring path, in the luminous flux direction is limited by the distance between the two light guides. That is, increasing the measurement path requires increasing the spacing of the light guides, which requires more precise mirror placement. In a correspondingly modified known solution, the prism surface is inclined by 45 ° facing the entrance of the light, and the prism surface is closed by air through a closing plate so that the prism surface provides total internal reflection. A prism with a chamber is provided on the extension of both light guides. Between the two prisms above,
There is a medium introduction slit that serves as a measurement path. Again, the length of the measuring path is limited by the distance between the two light guides. In any case, in order to carry out appropriate measurements,
The measuring device can be advantageously immersed in any container or free river, pond, etc., while removing the original measuring device itself for the analysis from the measuring point, for example it can be installed on a measuring trolley,
For in-process measurements, it can be placed at a sufficient distance or in the subchamber so as not to be affected by the possible high temperature or risk of contamination.

[0003]

However, in the case of these known measuring devices, it is necessary to increase the distance between the two light guides in order to obtain a sufficiently long measuring path for the light flux in the medium. The cross section of all measuring devices must be relatively large. This is especially necessary if one wishes to test liquids which have correspondingly large measuring paths due to the low absorbance. Thus, in order to test liquids of this kind, in some cases known measuring devices cannot be used. Furthermore, it is not possible to introduce such a large measuring device through a narrow opening in the container or in a relatively small container.

The object of the present invention is therefore to guide a light beam through a liquid medium, the external dimensions of which are as small as possible, in particular of which the cross-sectional area is small and which can have a measuring path of almost any size, It is an object of the invention to provide a measuring device which receives light completely or partially again and in particular performs spectroscopic analysis.

[0005]

The essence of the solution to this seemingly contradictory problem is that the measuring path or measuring chamber is arranged on one optical conductor or on an extension of the luminous flux emitted or received by this optical conductor. It is located outside the light diverting section. That is, surprisingly, the measurement path is located on the extension of one light guide and before or after the light redirect, rather than in the center between both light guides and its light redirect. . That is, the light guides can be juxtaposed as close to each other as possible, and thus the light diverting prism can be correspondingly made small and inexpensive. In this case, one of the two light guides is shortened more than the light diverting part and the light guides extending in parallel, a measurement path is placed between the light diverting part and the shortened light guide, and the unshortened light is guided. It is expedient if it extends substantially parallel to the conductor. That is, one light guide can reach near the light diverting part, while a measuring path continuing to the light diverting part is provided parallel to the light guiding part, and a second light guide is provided on an extension of the measuring path. To provide.
In this case, in any manner, a light guide that can be shortened to supply light or a non-shortened light guide is used, and another light guide is used to receive the light flux that has passed through the medium. By keeping the distance between both light guides as small as possible, it is possible to reduce the overall dimensions of the entire measuring device, and thus to introduce the measuring device through a narrow opening or into a small container despite the long measuring path. it can.

Since the measuring path is not provided between the two light diverting portions, there is only one rectangular prism in the passing light beam.
It is provided as a light diverting portion of 80 °, a light entrance and a light exit are provided at positions adjacent to the hypotenuse of the rectangular prism, mirror surfaces are provided on sides sandwiching a right angle, and a measurement path is provided in the light entrance or exit range of the prism. The measuring device can be manufactured particularly inexpensively by arranging the measuring device adjacent to, and in particular, arranging at right angles to the hypotenuse. Thus, on the one hand, a device is obtained whose cross-sectional area is as small as possible, yet the measuring path can be constructed practically arbitrarily long. In this case, the length of the measuring path is limited only by the total length of the device, or for any measuring path length, the device can be configured correspondingly long without the need to increase the cross-sectional area. Good. In this case, only one prism is sufficient for diverting light, and the distance between the two light guides is small, so that the prism is small, and therefore the advantage that it can be constructed inexpensively is obtained. Furthermore, the potential source of error based on the use of only one prism as a light redirecting element is
Significantly reduced compared to the solution using two prisms and providing a measuring path between the prisms.

The housings, which receive both light guides and prisms, can be opened laterally in the region of the measuring path, the measuring path being separable with respect to the uncontracted light guide and the end face of the shortened light guide. That is, the measurement path is actually
It is fully tentative from three sides, limited only to the end face and the side adjacent to the second light guide. Therefore, as compared with the medium introduction slit as the measurement path, the possibility of touching the medium to be measured is significantly improved when the medium is dipped in a container, a pipe, a river, a pond or the like. In this case, it is advantageous for error-free measurement if the measuring path is divided in the direction of the light guide arranged parallel to the measuring path by an opaque, in particular black, partition. A transparent closing disk can be provided between the measuring path and the light guide in the same row as this measuring path. In this way, the measuring light bundle can enter the measuring path and exit the measuring light path unimpeded, without the light conductor coming into contact with the medium.

Another solution to the problem of the measuring device, in which scattered light or fluorescence in the incident liquid medium in the liquid medium is detected by one of the parallel light guides, is the essence of the solution behind the incident light beam:
A single light deflecting portion is provided, and a free space is provided as a measuring chamber between the exit of the light deflecting portion and the second light conductor on the extension line of the second light guide. Thus, it is likewise possible to take advantage of the fact that two light guides can be provided parallel to the device, the mutual spacing being as small as possible. This is because the light emitted from one light guide reaches the measuring chamber by one deflection and causes the medium to emit fluorescence, which partially reflects and scatters the fluorescence. That is, to obtain a measuring device for fluorescence measurement or scattered light measurement, one half of the prism of the first solution can be removed. In this case, the only light deflection of the incident light beam is carried out by a mirror and / or a prism by 90 °, and the measuring chamber is arranged in front of the entrance to the second light guide and the exit from the light redirector, in particular both It is expedient to open the residue by means of a closing disc in front of the prism faces which are arranged substantially parallel to the light guide of FIG. Thus, also good tactile possibilities for the medium are obtained.

Since light scattering or fluorescence generation takes place at the exit of the light behind the prism, both light guides can have approximately the same length in the measuring device, and the light guides of the light guides. In front of it, a transparent closing disk may be provided which delimits the measuring chamber approximately at the height of the measuring device at right angles to the light guide for introducing the supplied luminous flux into the light diverting part. The second light guide can also be shortened, but in the case of fluorescence measurement or scattered light measurement, a larger distance to the original measuring point is not necessary.

In the case of the present invention, an adapter provided with a condenser lens for directing a light beam emitted from an optical conductor for supplying light in parallel and converging the light reaching the optical conductor for receiving light at an entrance of the optical conductor is a measuring point It is expedient if it is provided at each end of the light guide facing towards. Thus, light loss and measurement errors are best avoided. Furthermore, this avoidance is achieved by making the diameter of the light exit or entrance of the light guide smaller than 1 mm, in particular about 1/2 mm.
(Most preferably about 0.6 mm) can be achieved. Thus, the outer dimensions themselves are relatively small, thus helping to reduce the size of the overall measuring device as much as possible, yet a good light yield is obtained and thus sufficiently accurate measurements can be carried out.

In particular, when the above features and measures are combined, a measurement path of an arbitrary length of the medium can be achieved in a very narrow space, or a scattered light measurement or a fluorescence measurement can be performed, and the medium measurement chamber can be measured. It can be freely tentacled and the manufacturing cost is low.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; However, the dimensions, materials, shapes, relative positions, etc., of the components described in this embodiment are not intended to limit the scope of the present invention thereto, unless there is a specific description, and are merely illustrative examples. Nothing more than.

FIG. 1 has two parallel light guides which are guided out of the measuring device to a measuring instrument remote and redirect the light coming from one light guide twice and receive it again in another light guide. FIG. 3 is a side view of a measuring unit having a measuring device of a type in which a measuring path opened for introducing the medium to be tested is provided between the two optical conductors on an extension line of the shortened optical conductor. FIG. 2 is an enlarged vertical cross-sectional view of a measurement path device that performs light deflection twice and has a measurement path on an extension line of one light guide. In this case, the light guide arranged on the extension of the measuring path is shown outside the measuring device before it is introduced into the predetermined receiving opening. FIG. 3 is a plan view of the measuring device. FIG. 4 is a longitudinal sectional view of another measuring device for measuring fluorescence or scattered light.

In FIG. 1, two optical conductors 3 extend between a measuring device generally indicated by 1 and a measuring device 2 for analyzing the measurement result. That is, the distance between the measuring device 1 and the original measuring device 2 can be increased. In this case, the measuring device 1, which guides the light beam 4 through the liquid medium 25, collects it completely or partly and performs a spectral analysis with the measuring device 2, has inside it two essentially parallel light guides 3. , At the end of the light guide is redirected by a prism 5 to redirect light from the mouth 6 of one light guide 3 to the entrance 7 of another light guide 3 and between the light guides a measurement path 8 is provided. The test medium 25 can be introduced into the measurement path 8 through a side opening, and in the measurement path 8,
Allow the light flux to pass.

In this case, as is clear from FIG. 2, 1
A measuring path 8 is provided on the extension of one light guide 3 or on the extension of the light beam 4 emitted or received by this light guide and outside the light diverting section. The direction of light is indicated by arrow P in Figs.
In the case of the illustrated embodiment, the measuring path is provided immediately before the light guide 3 which receives the light, assuming the direction indicated by f. In FIG. 2, this light guide is shown just before installation, ie just before being inserted into the receiving opening 9 in the measuring device 1. That is, the light guide 3 is shortened in use as compared with another light guide 3, and the measurement path 8 is between the light diverting portions, that is, the prism 5 and the shortened light guide. Between The measuring path thus extends substantially parallel to the unshortened light guide 3.

In the case of FIG. 2, only one rectangular prism 5
Is provided as a light diverting portion having a total of 180 ° in the passing light beam 4. In this case, the slanted prism faces, which each make a 90 ° deflection, are formed by the closing plate 10 and the intermediate space 11
It is made up of total reflection. In this case, light is introduced and led out at a position adjacent to the hypotenuse of the rectangular prism 5, and the mirror surface is the closing plate 10 and the space 11.
It is on the side of a right angle with. In the case of this embodiment, the measuring path 8 is arranged adjacent to the prism 5 in the range of the light exit, at a right angle to the hypotenuse, and at the same angle of the light beam 4 to the hypotenuse.

The housing 12 of the measuring device 1 which receives both light guides 3 opens laterally in the region of the measuring path 8, which cuts off the medium from the light guides and thus the unshortened light. Separated for the end faces of the conductor 3 and the shortened light guide 3. In this case, the measuring path 8 is opaque in the direction of the light guide 3 arranged parallel to this measuring path,
In particular, it is separated by a black partition 13. Measuring path 8
A transparent closed disk 14 is provided between this measuring path and the light guides 3 in the same row. In some cases, the light guide that is not shortened in the illustrated embodiment can also be terminated at the same height as the shortened light guide. That is, both light guides can be shortened, in which case the incident light travels up to the prism in a section corresponding to the length of the measuring path. However, for the best possible interference-free measurement, the two light guides 3 whose ends are offset from each other by the length of the measuring path 8 in the longitudinal direction of the device 1.
The illustrated embodiment with is preferred.

As is apparent from FIG. 3, the above-described structure makes it possible to make the outer dimensions or the cross-sectional dimensions of the measuring device 1 relatively small, and to take the relatively long measuring path 8. Another embodiment of the measuring device 1 with two parallel light guides 3 in the housing 12 serves to detect scattered light or fluorescence in the medium on which the light bundle 4 is incident on one of the parallel light guides. In this case, likewise, this light guide for receiving light is shown outside the housing 12, and it is indicated by the arrow Pf2 that the light guide can be introduced into the corresponding opening 9 in order to complete the measuring device 1.

In the case of this embodiment, which is substantially similar to FIG. 2, the difference with respect to FIG. 2 is that, after the incident light beam 4, the light is deflected only once in the prism surface which is correspondingly constituted by the closing plate 10 and the space 11. And the free space as the measuring chamber 15 is provided on the extension line of the second light guide, in the exit of the light diverting part or in the angle space between the prism 5 and the second light guide 3. is there. In this case, the light is deflected only once by 90 ° by means of the prism 5, and the measuring chamber 15 is likewise delimited by a closing disk 14 in front of the entrance of the second light guide. The light outlet of the prism 5 is
Otherwise, limit the measurement chamber 15 which is open on the entire surface.

In this case, that is, both light guides 3 have substantially the same length in the measuring device 3. In front of the light guide 3 which emits light, a transparent closed disk 14 is provided which defines a measuring chamber 15. In this case, this closing disk is located approximately at the height of the measuring device 1 at right angles to the light guide 3 for introducing the supplied light beam 4 into the light diverting part (ie the prism 5). As is clear from FIG.
The closing disc 14 rests approximately on the prism 5 side-by-side with the light guide that supplies it. Furthermore, the thickness of the closing disk 14 allows the light receiving light guide 3 to be slightly shortened. That is,
The luminous flux is supplied from the separated measuring device 2 to the prism 5 by one optical conductor, and the luminous flux is purposely changed in the direction of the measuring chamber 15 in front of the mouth of the second optical conductor 3 for receiving light. Can be turned. In this case, in the above measurement chamber,
The light causes a fluorescence effect or a scattering effect, and the second light guide sends this fluorescence or scattered light to the measuring device 2. Here again, the measuring device 1 has, in an advantageous manner, good tactile accessibility to the medium and small external dimensions, so that the measuring device itself can be introduced into small containers or into containers with narrow openings.

In the case of both embodiments, the light beam emitted from the light guide 3 for directing light is directed in parallel to the end of the light guide 3 facing the measurement point, and the light reaching the light guide 3 for receiving light is reached. An adapter (16) is provided having a condenser lens 17 that focuses the light at the entrance 18 of the light guide. That is, the light exit or entrance 18 in the light guide 3 is less than 1 mm,
Preferably it has a diameter of 0.6 mm. Furthermore, the light used need not be visible light, but may be light waves in the invisible spectrum, depending on the measurement.

The measuring device 1 for making optical measurements or spectroscopic analyzes at a greater distance from the measuring device 2 has two parallel light guides, one of which is supplied with light and another. The light guide returns light guided through or scattered by the medium to the meter for analysis.
In this case, the measuring path 8 or the measuring chamber 15 is in front of one light guide, that is to say a light emitting light guide or, preferably, a light receiving light guide 3. That is, the light diverting part is
It is adjacent to the original measuring path and is not divided by the measuring path.
The external dimensions of the cross section of the measuring device 1 are correspondingly small.

[0023]

As described above, according to the present invention, the outer dimensions are as small as possible, especially the cross-sectional area is small, and
It is possible to obtain a measuring device which can have a measuring path of almost arbitrary size and guides the light beam through a liquid medium and re-receives it completely or partly, in particular for spectroscopic analysis.

[Brief description of drawings]

FIG. 1 has two parallel light guides which are guided out of the measuring device to a measuring instrument remote and redirect the light coming from one light guide twice and receive it again in the other light guide, FIG. 3 is a side view of a measurement combination with a measuring device of the type in which, between the two light guides, an extension of the shortened light guide is provided with an open measurement path for the introduction of the medium to be tested.

FIG. 2 is an enlarged vertical cross-sectional view of a measurement path device that performs light deflection twice and has a measurement path on an extension line of one light guide.
(In this case, the light guide placed on the extension of the measurement path is
It is shown outside the measuring device before it is introduced into the intended receiving opening)

FIG. 3 is a plan view of the measuring device.

FIG. 4 is a vertical cross-sectional view of another embodiment of a measurement device for fluorescence measurement or scattered light measurement.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Measuring device 2 Measuring instrument 3 Light guide 4 Light flux 5 Prism 6,7 Port of light guide 3 8 Measuring path 15 Measuring chamber 25 Medium Pf Arrow indicating light flux direction Pf2 Arrow indicating assembly direction

Claims (11)

[Claims] 1. A measuring device (1) for guiding a light beam (4) through a liquid medium (25) and receiving it completely or partly again, in particular for spectroscopic analysis, said measuring device essentially comprising: Two light guides (3) parallel to each other, and at the end of said light guide reflected by a mirror or prism (5) from the mouth of one light guide to the mouth of another light guide. The light is deflected, a measurement path (8) is provided between the mouth portions, the liquid medium for measurement (25) is introduced into the measurement path (8), and the light flux (4) is passed through the medium. A measuring path (8) or measuring chamber (15) on the extension of any light guide (3) or on the extension of the light bundle (4) sent or received by said light guide and A measuring device, which is provided outside the light diverting section. 2. One of the two light guides is shortened in comparison with the light diverting part and the light guides extending in parallel, the measuring path (8) comprising a light diverting part and a shortened light guide. Between
2. Measuring device according to claim 1, characterized in that it extends substantially parallel to the unshortened light guide (3). 3. A single rectangular prism (5) is provided as a 180 ° light diverting part in a light beam (4) which is introduced and led out, and the rectangular prism (5) has an entrance and an exit of light. At a position adjacent to the hypotenuse of the mirror surface, the mirror surface is provided on the surface sandwiching the right angle, and the measurement path (8) is adjacent to the prism (5) in the range of the entrance or exit of the light, especially on the hypotenuse. 2. The measuring device according to claim 1, wherein the measuring device is arranged at a right angle with respect to the measuring device. 4. A housing (12) for receiving both light guides (3) is open laterally in the region of the measuring path (8) and the measuring path (8) is not shortened. Measuring device according to claim 1, characterized in that it is limited to (3) and to the end face of the shortened light guide (3). 5. The measuring path (8) is divided in the direction of the light guide (3) arranged parallel to said measuring path by a non-translucent, in particular black, partition (13). The measuring device according to claim 1, wherein 6. A transparent closing disk (14) is provided between the measuring path (8) and the light guide (3) in the same row as the measuring path (8). Measuring device. 7. A measuring device (1) for guiding a light beam (4) through a liquid medium (25) and receiving it completely or partly again, in particular for spectroscopic analysis, wherein the scattered light or fluorescence is a light beam. In the type in which (4) is detected by one of the parallel light guides in the incident liquid medium, after the incident light beam (4) there is only one light diverting part,
On the extension line of the luminous flux, a free space is provided as a measuring chamber (15) in an angle space between the exit of the light diverting part and the second light guide. 8. The only diversion of the incident light bundle is carried out by 90 ° by means of a mirror and / or a prism (3),
A measuring chamber (15) is provided in front of the entrance to the second light guide and the exit from the light diverting part, in particular in front of the prism faces arranged substantially parallel to both light guides (1).
8. A measuring device according to claim 7, characterized in that it is defined by 4) and the rest is open. 9. Both light guides (3) have a measuring device (1).
In front of the light guide for conducting the light, the light guides (4) having almost the same length within the light guide (3) for introducing the supplied light beam (4) into the light diverting part are almost perpendicular to each other. 8. Measuring device according to claim 7, characterized in that at the height of the measuring device (1) a transparent closing disk (14) is provided which limits the measuring chamber (15). 10. Light reaching a light guide (3) that receives light by directing a light beam emitted from the light guide (3) that supplies light to each end of the light guide (3) facing the measurement location. Measuring device according to claim 1 or 7, characterized in that an adapter (16) is provided with a condenser lens (17) for focusing the light at the entrance (18) of the light guide. 11. A light outlet or entrance (18) for a light guide.
Has a diameter smaller than 1 mm, in particular a diameter of about 1/2 mm (about 0.6 mm), the measuring device according to claim 1 or 7.