DE19920193A1 - Apparatus for determining the absorption, scattering, fluorescence, and refraction of liquids and solids has an optical module, reflection module and right angle modules connected via an assembly block - Google Patents

Abstract

The optical module such as a sensor head module (2), a reflection module (3) and two 90 deg modules (4a, 4b) are connected via an assembly block (1) to be light-tight. The block consists of a base (1a) with four corner uprights (1b) that are flush with the base side walls and are formed upwards as a U-shape. Two of the U-shaped openings are located opposite each other in a common line with the optical modules (2, 3, 4a, 4b) rigidly fixed in them. Two optical modules are located opposite each other at a defined distance that acts as a shaft for the measuring medium. A light-tight lid (12) for opening and closing the shaft is arranged opposite the block base and an opening (1c) is located in the base for receiving measuring volume-determining elements which are formed as sample support inserts (5). The sample support is mounted on a sample support base (7) and can be inserted light-tight into the opening of the assembly block base. Apparatus for determining the absorption, scattering, fluorescence, and refraction of liquids and solids comprises a sensor head module (2) composed of an absorption, remission and refractive modules (18, 17, 15); and a reflection module (3). The sensor head equipped with a coupling mirror and the reflection module equipped with an opposing mirror form a multi-component reflection device. The optical module such as a sensor head module (2), a reflection module (3) and two 90 deg modules (4a, 4b) are connected via an assembly block (1) to be light-tight. The block consists of a base (1a) with four corner uprights (1b) that are flush with the base side walls and are formed upwards as a U-shape. Two of the U-shaped openings are located opposite each other in a common line with the optical modules (2, 3, 4a, 4b) rigidly fixed in them. Two optical modules are located opposite each other at a defined distance that acts as a shaft for the measuring medium. A light-tight lid for opening and closing the shaft is arranged opposite the block base and an opening (1c) is located in the base for receiving measuring volume-determining elements which are formed as sample support inserts (5). The sample support is mounted on a sample support base (7) and can be inserted light-tight into the opening of the assembly block base.

Description

Technical field

Analytics, environmental, quality and process monitoring, spectroscopy, absorption, remission, Scattering, fluorescence, refraction.

State of the art Absorption spectroscopy

Conventional absorption methods are used to detect absorbing substances in liquids, gases and solids (measuring volume). Radiation of a defined wavelength is coupled into the measurement volume. On their way through the Meßvolu men, the coupled radiation is weakened by absorbing substances. After a defined distance, the coupling radiation is coupled out again and directed to an optoelectronic receiver which registers the weakened intensity I. The quotient of the weakened and non-weakened intensity I ₀ is the transmission T:

T = I / I ₀ = exp (-α _T x) (1)

This law by Bouguer-Beer-Lambert describes the relationship between transmission and the total absorption coefficient α _T (for the sake of simplicity, the scatter has been neglected here). The term x is the path that the coupling radiation travels in the measurement volume. [1], [2]

Reflectance spectroscopy

The reflectance is made up of diffuse reflectance and specular or directional Reflection together.

(a) Remission

The reflectance R is the diffuse reflection of radiation from matter (measuring volume). It is a measure of the intensity of the photons reflected against the direction of incidence. In the classic sense, these are scattered photons. The remission is determined by the scattering capacity (scattering coefficient β) and absorption capacity (total absorption coefficient α _T ,) of the measuring volume. For the sake of simplicity, absorption will dominate in the following. The theory of Kubelka and Munk is used to describe the remission mathematically. In the case of an infinitely extended measurement volume (e.g. deep water), the remission is proportional to the quotient of the scattering coefficient and the absorption coefficient,

R _S ~ β / α _T (2).

If fluorescence is also generated by the radiation incident in the measurement volume, then the remission is determined in the broader sense not only by the scattering but also by the fluorescence ability, which is determined by the product of the fluorescence quantum yield Q _F and the absorption coefficient of the fluorophores α _{F of} the measurement volume (Q _F α _F ) is characterized. The fluorescence contribution to the remission of large measurement volumes is determined by the quotient

R _F ~ Q _F α _F (λ _E ) / [α _T (λ _E ) + (α _T (λ _F )] (3)

controlled, where λ _E and λ _{F are} the wavelengths of the incident radiation and fluorescence. In many cases of transmitting measurement volumes, the absorption at the wavelength of the incident radiation is greater than the absorption at the fluorescence wavelength (e.g. in the case of eutrophicated surface waters). Then (3) merges into (4):

R _F ~ Q _F α _F (λ _E ) / α _T (λ _E ) (4)

The formulas (2) and (4) are characterized by the same mathematical structure. The In both cases, reflectance is proportional to the scattering and fluorescence ability and on the other hand, inversely proportional to the total absorption.

(b) reflection

Reflection spectroscopy is preferably used to examine solid surfaces used. The radiation that is directly reflected or directed by a surface is thereby analyzed (reflection law), which provides information about the spectral reflectivity. When analyzing the diffuse reflectance R of transmitting solid, liquid and gas moderate measurement volume (see (a)) is the one occurring at the interface with the measurement volume specular reflection i. d. R. a disturbance variable, which is masked out by suitable measuring arrangements becomes.

The specular or directional reflection R _G depends, among other things, on the refractive index n of the measurement volume. Since the measurement volume absorbs in many cases, the refractive index that is customary for reflection is determined in addition to the refractive power by the absorption capacity of the measurement volume. The refractive index consists of a real part and an imaginary part (complex number):

R _G = ((n-1) / (n + 1)) ² (5)

with n = n _real + n _imaginary . Formula (5) is a simplified representation for the air / measurement volume interface with vertical radiation. The refractive index is practically determined goniometrically or interferometrically as a real part. [1], [2]

In PCT / DE 97/02718 a method is proposed that the absorption and reflectance based on the complete absorption of the coupling radiation in the measuring volume trimmed. Radiation of a defined wavelength is injected into the measurement volume to be examined, which is preferably transmissive. The measuring volume is there between two opposing mirrors. The mirrors are designed in such a way that a sufficiently high number of reflections the way of the coupling mirror Coupled radiation is so long that it is completely absorbed in the measuring volume can be. Complete absorption is a prerequisite for the development of remission according to the formulas given above (term here: saturated long-term remission). The saturated long-term remission is arranged with a on the coupling mirror and on the Measuring volume aligned photoelectronic receiver in conventional reflectance measuring geome trie, i.e. backwards, measured. The measurement signal is according to formula (2) in the case of scatter and described in the case of fluorescence according to formula (4).

A second essential measuring process takes place synchronously with this. The coupling mirror (or also the counter mirror) is partially transparent, e.g. B. 5% transmission and 95% reflectivity. Consequently, after each reflection or after each revolution, part of the coupling radiation transmitted by the measuring volume passes through the coupling mirror and arrives at a second receiver arranged immediately behind the coupling mirror. If the fluorescence and scattering photons passing through the partially transparent mirror are neglected, the intensity I _{Tr of} the transmitted coupling radiation is approximated by the following formula:

I _Tr ~ m / α _T (6)

The term m is a constant that is characteristic and known for the permeability of the coupling mirror. The total absorption coefficient α _T can thus be determined directly from (6). Compared to classic absorption spectrometry (Lambert-Beer Exponential Law) (6) is characterized by a higher sensitivity, which leads to deeper detection limits and higher accuracies. With increasing α _T , I _Tr decreases. This makes sense, since with increasing α _T the mean path length of the injected radiation decreases until it is almost completely absorbed in the measuring volume and thus the number of reflections or revolutions decreases. This also reduces the intensity I _Tr of the coupling radiation passing through the partially transparent mirror. In addition, the intensity I _{Tr is} also determined by the mirror constant m. The larger m, ie the smaller the reflectivity or the greater the permeability of the coupling mirror, the higher I _Tr .

By inserting α _T in the formulas (2) and (4), the scattering and fluorescence ability β and Q _F α _{F can also} be determined indirectly. The ambiguity of classic reflectance spectroscopy is eliminated by the combination with the absorption spectroscopy presented above.

Another measurement process is also carried out. With a separate and internal Radiation source is irradiated and an interface of the optical window / measurement volume specularly reflected radiation with an optoelectronic receiver arranged at the rear ger registered. The refraction of the measuring volume is then determined from this in accordance with formula (5). PCT / DE 97/02718 describes a device for carrying out the method. It individual modules are presented that differ from one another in their defined arrangement ne systems result. The modules are in the individual sensor head module with absorption, Remission and refraction module, reflection module and 90 ° module. The absorption module  contains a partially transparent plane mirror as a coupling mirror. The reflection module contains a concave mirror as a mirror. Both of them arranged opposite one another form a multiple reflection xion device. The absorption module contains one immediately behind the coupling mirror optoelectronic receiver for measuring the intensity of the transmitted coupling radiation (absorption). The remission module contains an optoelectronic receiver Measurement of the intensity of the remission (fluorescence, scattering). The refraction module contains a radiation source and an optoelectronic receiver for measuring the at the Interface optical window / measuring volume specularly reflected intensity (refraction).

Problem / task

The defined arrangement of the above. Modules with one another have basic features. These are not sufficient for specific applications in the laboratory, in industry and the environment. This applies in particular to use as a laboratory spectrometer, flow and immersion chamber Measuring probe. Devices have to be developed for this.

solution

The speech 1 is explained. For this purpose, Fig. 1 (top view, side view below) is considered, which shows a universal laboratory spectrometer with a cuvette holder. The mounting block ( 1 ) is U-shaped, with two U-shaped recesses open at the top opposite each other, which are formed from the corner posts ( 1 b). The corner posts close below with the base ( 1 a). The corner posts are flush with the plinth side walls. The U-shaped recesses take the cuboid optical modules sensor head ( 2 ), reflection module ( 3 ) and two 90 ° modules ( 4 a, b), which are preferably locked with screw connections and are designed as a light-tight connection. There are two optical modules facing each other on a common line at a defined distance. The base has threads with which a fastening supply, if necessary, for. B. is possible on base plates. The space inside the corner posts or between the opposing optical modules is the shaft for the measuring volume.

The coupling radiation is directed into the space between the sensor head and the reflection module ( 3 ) via the sensor head ( 2 ) and is reflected several times between the two (see PCT / DE 97/02718). According to the preamble, the sensor head consists of the refraction module ( 15 ), the reflectance module ( 17 ) and the absorption module ( 18 ) with a partially permeable coupling mirror. The reflection module ( 3 ) consists of the counter mirror. The refraction module ( 15 ) is replaced by a cuboid without a measuring function if the corresponding application does not require the measurement of the refractive index. If required, modules ( 4 a) and ( 4 b) for measuring lateral scatter and fluorescence (e.g. 90 °) can also be installed in the mounting block. If necessary, these modules can be equipped with radiation cross-section converters.

The base of the mounting block contains a continuous opening ( 1 c) for receiving measuring volume-determining elements, which are designed in particular as sample holder inserts with sample holder bases and holding elements. In Fig. 1 this is a cuvette insert ( 5 ). The cuvette insert is mounted on a sample holder base ( 7 ) by means of a fastening ( 11 ). This base ( 7 ) is connected to the mounting block via the two bores ( 7 a) and the corresponding threads ( 1 e) in the base ( 1 a). Using the holes ( 7 b) in the base ( 7 ), the spectrometer can be mounted on base plates or the like if necessary. The base can also serve as a stand. Supporting elements ( 7 c) can be arranged between the base and the sensor head. The cuvette insert contains two pressure springs ( 6 a) and ( 6 b) for fixing a cuvette ( 8 ), which is pressed against the sensor head and the cuvette insert wall ( 10 ). The wall ( 10 ) contains an opening for the passage of lateral scatter or fluorescence. On the sample support base can be attached to the application adapted brackets, so that instead of a liquid cuvette other preparations such. B. solids can be included. The laboratory spectrometer is equipped with a light-tight cuvette lid ( 12 ) with ball pressure screws ( 13 ). The cover is rotatably mounted on the mounting block via connections for the cover rotation axis ( 14 ). For operation with a flow cell, the cover is rigidly connected to the mounting block via the connections ( 14 ), fixed with ball pressure screws and has an opening for connecting a flow cell. For this application, the bases ( 1 a) and ( 7 ) contain openings ( 9 ).

Another favorable form of the mounting block is that the openings for the on The optical modules are circular and the modules themselves are cylindrical. These will screwed into the openings or fixed laterally with screws. Also the opening for the Inclusion of cylindrical measuring volume determining elements can be circular his.

According to claim 2, the assembly block consists of the base and instead of the 4 corner posts of two opposing and continuous receiving blocks ( 19 a) ( Fig. 2). The mounting blocks and base form an upward U-shape. Sensor head and reflection module are picked up and fastened on the open and opposite sides. A defined distance is realized between the two optical modules. This room serves as a shaft for the positioning of measuring volume-determining elements. The optical modules are either attached to the end faces of the mounting blocks or to the inside, or the attachment is carried out on the inside and end face. Fig. 2 (top view) shows the latter case. On the two recording blocks ( 19 a) contain on their end faces recesses for receiving sensor head ( 2 ) and reflection module ( 3 ). If necessary, the mounting blocks have openings for mounting 90 ° modules.

Starting from claims 1 and 2, the mounting block according to claim 3 is such that the mounting blocks ( 19 b) frame the sensor head and the reflection module completely to the side (see Fig. 3). This offers greater stability and protection when used under adverse measuring conditions. If required, these mounting blocks also have openings for receiving 90 ° modules. Another favorable modification is that the mounting block completely encloses the optical modules. This system can be cuboid or cylindrical.

Claim 4 is a favorable training for the case when the measurement volume is reflective. These can be solids with gloss properties, for example. To investigate such Measuring volumes with the help of the multiple reflection running over coupling and counter mirrors is the reflection module or the sensor head in one of the two 90 ° openings of the Mounting blocks assembled. The sensor head and reflection module are therefore not aligned opposite a common straight line, but form one with respect to their normal  right angle. The solid to be examined is inserted into the assembly block using a insertable insert in such a way that the solid in the beam path of the Multiple reflection is localized and its normal with the normal of sensor head and Reflection module forms an angle of 45 °. The solid actively takes part in the Multiple reflection part. The opening directly opposite the sensor head is marked with a provided light-tight closure. If the solid is transmissive, an optoelek becomes there tronic receiver for measuring the radiation transmitted through the solid arranged. The openings provided for the optical modules are designed such that every opening can accommodate every optical module.

Of claim 5 is based on the Fig. 4 illustrates that documents a device which is particularly suitable as Durchflußkammer- immersion chamber and measuring probe. A hollow cylinder ( 20 ) has six openings. There are in each case an opening ( 21 ), ( 22 ) in the base and top surfaces, which are referred to below as end surfaces of the cylinder. These two end face openings are arranged opposite each other and serve to receive the insert ( 27 ) for the sensor head ( 2 ) and the reflection module ( 3 ). According to the preamble, the sensor head ( 2 ) consists of the absorption, reflectance and refraction module ( 18 ), ( 17 ), ( 15 ) and contains the coupling mirror. The reflection module arranged opposite the sensor head contains the counter mirror. The multiple reflection of the coupling radiation occurs between the two mirrors. The measuring volume is located in elements determining the measuring volume between the sensor head and the reflection module. Four openings ( 23 ), ( 24 ), ( 25 ), ( 26 ) are located in the cylinder jacket. Two of them face each other and thus form a continuous opening. The openings ( 23 ), ( 24 ) take measurement-determining elements ( 28 ) such as window and sample holder inserts. The other openings ( 25 ), ( 26 ) in the cylinder jacket are provided for inserts ( 29 ), ( 30 ) for holding optical filters.

The sensor head insert ( 27 ) is designed as a support for the sensor head ( 2 ) and attached to a cylindrical end part ( 31 ). The reflection module ( 3 ) is designed as an insert and is also attached to a cylindrical end part ( 32 ). By means of these end parts, these inserts can be inserted into the cylinder ( 20 ) through the opening ( 21 ), ( 22 ) in the two cylinder end faces. The sensor head ( 2 ) is located on the coupling mirror side in the immediate vicinity of the measuring volume. The reflection module ( 3 ) (counter mirror) is also located in the immediate vicinity of the measuring volume with its reflecting side.

The filter inserts ( 29 ), ( 30 ) serve to hold optical filters. These are arranged directly in front of two optoelectronic receivers ( 35 ), ( 36 ) and are used, for example, in the fluorescence measurement as a long-pass filter to suppress the elastic scatter. The inserts are attached to cuff-shaped end parts ( 33 ), ( 34 ). These end pieces are adapted to the shape of the cylinder jacket. They are inserted into the cylinder through the openings ( 25 ), ( 26 ) in the cylinder jacket.

The insert for elements ( 28 ) determining the measurement volume is preferably designed as a window insert. The window insert is mon tierbar on two cuff-shaped end parts ( 37 ), ( 38 ) which are adapted to the jacket shape of the cylinder. The insert is inserted into the cylinder via the openings ( 21 ), ( 22 ) in the cylinder jacket. The window insert is a scaffold equipped with optical windows ( 40 ), ( 41 ), ( 42 ), ( 43 ) and is suitable for liquids and gases that flow through this insert through a continuous opening ( 39 ) (flow or immersion operation). The surface normal of the optical window is arranged perpendicular to the measuring volume flowing through. Two neighboring windows each form a right angle. Two windows facing each other are parallel. The opposite windows ( 40 ) and ( 42 ) are directly in front of the coupling-in mirror surface of the sensor head ( 2 ) or in front of the mirror surface of the reflection module ( 3 ) as well as the opposite windows ( 41 ) and ( 43 ) in front of the two deflecting mirrors ( 44 ), ( 45 ) (90 ° fluorescence / scatter) localized. The window insert is hermetically sealed against the inside of the cylinder or against the sensor head and reflection module. For this purpose, the windows are inserted tightly into the frame, which is attached to the two opposing cuff-shaped end parts ( 37 ), ( 38 ), which in turn are firmly mounted on the cylinder. The window insert can be assembled from individual parts or can be designed as a monolithic shape.

The end parts ( 31 ), ( 32 ), ( 33 ), ( 34 ), ( 37 ), ( 38 ) are intended to provide a tight seal of the interior of the cylinder or, depending on the application, to seal the sensor head and reflection module hermetically from the environment. Two end parts ( 31 ), ( 32 ) are cylindrical, which close the openings in the cylinder end faces ( 21 ), ( 22 ). For this purpose, these are inserted and screwed into the cylinder using a sealing O-ring ( 46 ), ( 47 ). Four end parts ( 33 ), ( 34 ), ( 37 ), ( 38 ) are cuff-shaped to match the Zylin dermantel and are attached with a seal on the outer wall of the cylinder. As stated above, the end parts also serve to fasten the corresponding inserts. The cylindrical end part ( 31 ) for the sensor head insert ( 27 ) has an opening through which electrical and / or optical waveguide cables are guided tightly to the outside. Furthermore, the cuff-shaped end parts ( 37 ), ( 38 ) for the window insert have an opening through which the measuring volume (liquid or gas) can get into the window insert.

In the described device, the coupling radiation is coupled in via the sensor head ( 2 ) into the measurement volume, which passes through the windows ( 40 ) and ( 42 ) several times as a result of the multiple reflection between the coupling mirror and the counter mirror. The intensity of the transmitted coupling radiation and the reflectance are measured backwards to the coupling radiation, with optoelectronic receivers in the absorption module ( 18 ) and reflectance module ( 17 ) located in the sensor head and behind the window ( 40 ). The window ( 40 ) is further exposed to radiation from the refraction module ( 15 ). A receiver in the refraction module registers the radiation reflected by the interface window ( 40 ) / measurement volume, with which the refractive index of the measurement volume is determined. The radiation, such as fluorescence and / or scattering, coming from an angular range of 90 ° (as a central angle) passes through the windows ( 41 ) and ( 43 ). This radiation passes deflection mirrors ( 44 ), ( 45 ) arranged directly on the windows ( 41 ) and ( 43 ). These mirrors each apply an optical waveguide ( 48 ), ( 49 ) (e.g. a glass rod with a diameter of 5 mm), which passes the radiation past the sensor head ( 2 ) to optoelectronic receivers ( 35 ), ( 36 ) located behind the sensor head ) leads. Deflecting mirrors ( 50 ), ( 51 ) and - suitable optical filters are arranged in front of these receivers ( 29 ), ( 30 ).

The sensor head insert ( 27 ) can also serve as a carrier for further elements such as electronics, power supply, etc.

According to claim 6 z. B. in the case of the immersion chamber measuring probe, see the two openings ( 39 ) in the window insert for the flow through the measuring volume with special orifices. These are screwed in and are used to shade disruptive ambient light.

Claim 7 describes the possibility in the case of the flow chamber measuring probe to provide the two openings ( 39 ) in the window insert for flowing through the measuring volume with pipe adapters. These are screwed in and are used to connect the measuring probe to the pipe or hose.

According to claim 8, the insert for measuring volume-determining elements ( 28 ) can also be a sample holder insert which is mounted on a closing part which is designed as a base. The base is adapted to the jacket shape of the cylinder. The insert is inserted into the cylinder through the two through openings in the cylinder jacket. The end part located opposite the base is a cover which closes the opening for the sample feed in a light-tight manner. The sample holder insert can have optical windows to protect the sensor head, reflection module and 90 ° deflection mirror. These can also be omitted for certain sample carriers, e.g. B. in the case of a cuvette filled with a liquid, in which the cuvette walls themselves act as protection. This version is e.g. B. usable as a laboratory spectrometer. Analogously to Fig. 1, the cylinder is attached to the base as well as to support elements adapted to the cylinder shape.

The following statements refer to both devices, i.e. to the universal Laboratory spectrometer (claims 1-4) and on the immersion and flow chamber measuring probe (Claims 5-8).

According to claim 9, the mirror is placed in such a position that the one coupling mirror plane and the counter mirror plane are parallel, the optical axes of counter and coupling mirror only in the vertical direction a distance other than zero have, and both mirrors are located at a defined distance from each other. The Vertical displacement is done in such a way that the images of the fiber optic end faces follow the first reflection of the coupling radiation at the counter mirror at a mirror distance of twice the focal length on the lower, opposite the fiber optic end faces Area of the coupling mirror are localized. The end faces and their pictures are located doing so on a common vertical. The mirror distance is then set so that the End faces of the optical fibers of the sensor head between single and double burning are localized wide of the counter mirror, whereby no overexposure of the mirror may occur. In many cases it is sufficient to carry out a rigid installation without adjustment elements can. If necessary, simple adjustment elements (e.g. elongated holes and spacer elements) arranged, the one vertical translation and one leading along the optical axis Allow horizontal translation of the entire reflection module.

According to claim 10, the reflection module is replaced by a radiation trap. Sensor head and radiation trap face each other. This is advantageous, for example, for measurement volumes whose spectral absorption behavior is characterized by strong local maxima and minima. The coupling radiation is fully absorbed in the absorption maximum after a short distance. A signal is generated that is proportional to β / α _T. The radiation is hardly absorbed in the absorption minimum. A signal is generated that is proportional to β. The combination of both signals then gives the total absorption and scattering coefficients of the measurement volume. It is assumed that either the scattering coefficient exhibits a uniform spectral behavior or that this spectral behavior is known (e.g. exponential curve).

According to claim 11, spatially resolving receivers (eg CCD cameras) are used. In the 90 ° position, such a camera determines the size of the radiating surface of the measurement volume facing it. The size of this area (e.g. as a relative intensity distribution) is an inverse measure of the total absorption coefficient α _T (spatially resolved measurement). The camera also measures the intensity of the lateral scatter / fluorescence, which allows the determination of β and α _F Q _F. Instead of the camera, an optical module can also be arranged in which different receivers (with or without an upstream light waveguide) are located at defined and different positions in the receiver plane and each register radiation from different surface elements of the radiating surface. The receivers are aligned with individual surface elements of the measuring volume via diaphragms.

Since the devices described are suitable for recording flowing measuring volumes, is described with claim 12, a training with which the flow rate is measured. For example, the system is connected to a pipe in which one Liquid flows. It becomes the optoelectronic receiver, which is the one in the sensor head localized partially transparent coupling mirror registered transmitted radiation, considered. The receiver is located at a defined distance d behind the coupling mirror. This location is representative of the geometric radiation conditions Conditions in the plane upstream of the coupling mirror by the distance d. This Level or the corresponding area near the level is caused by coupling radiation in this way flooded that along the direction of flow of the measuring volume, some bright spots of the coupling radiation are visible due to the imaging effect of the concave mirror in the reflect xionsmodul and the multiple reflection arise. In the flowing measuring volume Particles or density fluctuations that flow through exactly these radiation spots darken them intensity that hits the receiver, when you leave the spot it shows up again Brightening. Light-dark phases are generated. An intensity frequency arises. The Receiver behind the partially transparent mirror is operated as a frequency meter. The Frequency is an expression of the particle speed and thus a measure of the flow dizziness. Similarly, the remission or 90 ° module receiver can be used as a frequency knives are operated.  

Reference numerals Fig. 1

1

Assembly block

1

a base

1

b corner post

1

c Opening in the base

1

d Thread in the base

1

e Thread in the base

2nd

Sensor head module

2nd

a Sensor head attachment

3rd

Reflection module

3rd

a Mounting reflection module

4th

a 90 ° module with optoelectronic receiver for scattering / fluorescence

4th

b 90 ° module with optoelectronic receiver for scattering / fluorescence

5

Cell insert

6

a Pressure spring in the cuvette insert

6

b Pressure spring in the cuvette insert

7

Sample holder base (e.g. base for cuvette insert)

7

a Bore in the cell insert base

7

b Hole in the cell insert base

7

c U-shaped support for sensor head module

8th

Cuvette

9

Opening for flow cell

10th

Cell holder wall

11

Fastening the cuvette insert on the cuvette insert base

12th

cover

13

Lid lock (ball pressure screws)

14

Connection for cover axis of rotation

15

Refraction module with radiation source and optoelectronic receiver for refraction

16

Attachment for refraction module

17th

Remission module with optoelectronic receiver for remission

18th

Absorption module with optoelectronic receiver for absorption

Fig. 2

19th

a recording block

Fig. 3

19th

b Recording block

Fig. 4

2nd

Sensor head module

3rd

Reflection module, designed as a cylindrical insert

15

Refraction module with radiation source and optoelectronic receiver for refraction

17th

Remission module with optoelectronic receiver for remission

18th

Absorption module with optoelectronic receiver for absorption

20th

hollow cylinder

21

Opening in the cylinder end face

22

Opening in the cylinder end face

23

Opening in the cylinder jacket

24th

Opening in the cylinder jacket

25th

Opening in the cylinder jacket

26

Opening in the cylinder jacket

27

Insert for sensor head

28

Use for elements determining the measuring volume (e.g. window insert)

29

Filter insert (90 ° module)

30th

Filter insert (90 ° module)

31

cylindrical end piece for sensor head

32

cylindrical end part for reflection module

33

cuff-shaped end piece for filter insert

34

cuff-shaped end piece for filter insert

35

optoelectronic receiver for 90 ° fluorescence scattering

36

optoelectronic receiver for 90 ° fluorescence / scattering

37

cuff-shaped end piece for window use

38

cuff-shaped end piece for window use

39

Openings for measuring volumes in use for elements determining the measuring volume

40

Optical window in front of the sensor head

41

Optical window in front of deflecting mirror (90 ° module)

42

Optical window in front of reflection module

43

Optical window in front of deflecting mirror (90 ° module)

44

Deflecting mirror (90 ° module)

45

Deflecting mirror (90 ° module)

46

O-ring

47

O-ring

48

Light guide (90 ° module)

49

Light guide (90 ° module)

50

Deflecting mirror (90 ° module)

51

Deflecting mirror (90 ° module)

literature

[1] BERGMANN and SCHAEFER: Textbook of experimental physics. Optics. Berlin - New York, Walter de Gruyter, 1993.
[2] SCHMIDT, W .: Optical Spectroscopy. Weinheim-New York-Basel-Cambridge-Tokyo, VCH publishing company, 1994.
[3] BAUMBACH, G .: Air pollution control. Berlin-Heidelberg-New York, Springer Verlag, 1992.
[4] DE 41 04 316A 1
[5] DE 41 24 545A1
[6] DD 301 863 A7
[7] MITTENZWEY, K.-H., J. RAUCHFUß, G. SINN, H.-D. KRONFELDT: A new fluo rescence technique to measure the total absorption coefficient in fluids. Fres. J. Anal. Chent, 354 (1996) 159-162.
[8] DE 43 37 227 A1
[9] KORTÜM, G .: Reflection spectroscopy. Berlin-Heidelberg-New York, Springer Verlag, 1969.
[10] COLWELL, RN: Manual of remote sensing. Falls Church, The Sheridan Press, 1983.
[11] PCT / DE 97 10 2718.

Claims (12)

1. Device preferably for use in the laboratory for the synchronous determination of the absorption, scattering, fluorescence and refraction of liquids and solids (measuring volume) with a sensor head module ( 2 ) consisting of the absorption, remission and refraction module ( 18 ), ( 17 ), ( 15 ) is composed, and a reflection module ( 3 ), the sensor head equipped with a coupling mirror and the reflection module equipped with a counter mirror forming a multiple reflection device, where radiation of defined wavelengths is coupled in via the coupling mirror, the coupling by means of optical fibers takes place, the end faces are in the coupling mirror plane, this coupling radiation is almost completely absorbed due to long distances in the measuring volume, with a direct bar behind the coupling mirror, which is partially transparent, localized receiver the transmitted coupling radiation and with an aimed at the measuring volume and on the coupling mirror, the receiver locates the remission directed against the direction of incidence (saturated long-path remission), and the radiation specularly reflected at the glass / measurement volume interface as well as optionally the scattering and fluorescence directed at an angle in the range of 90 ° by means of optical 90 ° modules ( 4 a), ( 4 b) are measured, characterized in that
that the optical modules such as a sensor head module ( 2 ), a reflection module ( 3 ) and two 90 ° modules ( 4 a), ( 4 b) are joined together in a light-tight manner via an assembly block ( 1 ) which consists of a base ( 1 a) there are four corner posts ( 1 b), which are flush with the base side walls and are U-shaped open at the top, two of the four U-shaped openings facing each other along a common line, the optical modules ( 2 ) , ( 3 ), ( 4 a), ( 4 b), rigidly fixed in these openings and two optical modules are located opposite each other at a defined distance, the space extending between the optical modules serves as a shaft for the measuring volume, the mounting block base ( 1 a) is arranged opposite a light-tight closure ( 12 ) for opening and closing the shaft provided for the measurement volume supply, in the base ( 1 a) for receiving measurement volume-determining El ementen an opening ( 1 c) is localized, the measuring volume-determining elements are designed as sample holder inserts ( 5 ), the sample holder being mounted on a sample holder base ( 7 ) and being light-tightly insertable into the opening ( 1 c) of the mounting block base ( 1 a). 2. Apparatus according to claim 1, characterized in that the sensor head ( 2 ) and reflection module ( 3 ) are joined together via a mounting block which consists of a base with two receiving blocks ( 19 a) located thereon, which are flush with the base side walls and u- are designed to be open at the top, the two U-shaped openings facing each other along a line and the optical modules ( 2 ), ( 3 ) being rigidly fixed in these openings. 3. Apparatus according to claim 2, characterized in that the sensor head ( 2 ) and reflection module ( 3 ) are completely framed laterally by mounting blocks ( 19 b) or completely enclosed. 4. The device according to claim 1, characterized in that in the case of reflecting measurement volumes, the reflection module ( 3 ) or the sensor head ( 2 ) is arranged in one of the two openings for the 90 ° modules, the measurement volume to be examined by means of an insertable insert in the Way is held that the measuring volume is localized in the beam path of the multiple reflection and directs the coupling radiation from the sensor head to the reflection module and vice versa, the opening directly opposite the sensor head in the mounting block is provided either with a light-tight closure or with an optoelectronic receiver. 5. Device preferably for use as a flow and immersion chamber measuring probe in the synchronous determination of the absorption, scattering, fluorescence and refraction of liquids and gases (measuring volume) with a sensor head module ( 2 ) consisting of absorption, remission and refraction modules ( 18 ), ( 17 ), ( 15 ), and a reflection module ( 3 ), the sensor head equipped with a coupling mirror and the reflection module equipped with a counter mirror forming a multiple reflection device, where radiation of a defined wavelength is coupled in via the coupling mirror, the coupling tion by means of optical fibers, the end faces of which are in the coupling mirror plane, this coupling radiation is almost completely absorbed due to long distances in the measurement volume, with a receiver located directly behind the coupling mirror, which is partially transparent, the transmitted coupling radiation and with one on the measurement volume-oriented receiver located at the coupling mirror, the remission directed against the direction of incidence (saturated long-term remission), and the radiation specularly reflected at the glass / measurement volume interface, as well as optionally the scattering and fluorescence directed at an angle in the range of 90 ° be measured by means of optical 90 ° modules ( 4 a), ( 4 b), characterized in that
that a hollow cylinder ( 20 ) has six openings for receiving inserts, each by an opening ( 21 ), ( 22 ) in the two cylinder end faces and four openings ( 23 ), ( 24 ), ( 25 ), ( 26 ) in Cylinder jacket are located, the opposite end face openings ( 21 ), ( 22 ) each having the insert ( 27 ) for the sensor head ( 2 ) and the reflection module ( 3 ) designed as an insert, the two opposite jacket openings ( 23 ), ( 24 ) an insert for elements ( 28 ) determining the measuring volume and the other two opposite jacket openings ( 25 ), ( 26 ) receiving a filter insert ( 29 ), ( 30 ),
the sensor head insert ( 27 ) is designed as a support for the sensor head ( 2 ) and can be mounted on a cylindrical end part ( 31 ) which can be inserted into the cylinder via the opening in one cylinder end face ( 22 ), and the sensor head ( 2 ) on the coupling-in mirror side is arranged in the immediate vicinity of the insert for elements ( 28 ) determining the measurement volume,
the reflection module insert is formed by the reflection module ( 3 ) itself and can be mounted on a further cylindrical end part ( 32 ) which can be pushed into the cylinder via the opening in the other cylinder end surface ( 21 ), and the reflection module on the reflection side in the immediate vicinity of the insert for elements ( 28 ) determining the measuring volume and the sensor head ( 2 ) are arranged at a defined distance from one another,
the filter inserts ( 29 ), ( 30 ) are designed as supports for optical filters and can be mounted on sleeve-shaped end parts ( 33 ), ( 34 ) adapted to the jacket shape of the cylinder, the inserts via the openings ( 25 ), ( 26 ) in the cylinder jacket in the cylinders can be inserted and the filters are arranged in the immediate vicinity of optoelectronic receivers ( 35 ), ( 36 ),
the insert for measuring volume-determining elements ( 28 ) is preferably designed as a window insert, the window insert can be mounted on two opposing, cuff-shaped end pieces ( 37 ), ( 38 ) adapted to the jacket shape of the cylinder, the window insert via the two openings ( 23 ) , ( 24 ) in the cylinder jacket can be inserted into the cylinder, the window insert has two opposite walls with openings ( 39 ) for the measuring volume and four vertical walls with optical windows ( 40 ), ( 41 ), ( 42 ), ( 43 ) - side walls The two opposing optical windows ( 40 ), ( 42 ) each reflect directly in front of the sensor head ( 2 ) and reflection module ( 3 ) and the two optical windows ( 41 ), ( 43 ) lying opposite each other perpendicularly in front of the deflection ( 44 ), ( 45 ) are arranged,
the cylindrical end parts ( 31 ), ( 32 ) in the two end face openings ( 21 ), ( 22 ) are each provided with an O-ring ( 46 ), ( 47 ), and the cuff-shaped end parts ( 33 ), ( 34 ), ( 37 ), ( 38 ) are pressed in the openings in the cylinder jacket with a sealing ring against the cylinder jacket by means of screws, so that the sensor head ( 2 ) and reflection module ( 3 ) are hermetically sealed, the cylindrical end part ( 31 ) for the sensor head insert being an opening for the passage of cables and the two opposing cuff-shaped end parts ( 37 ), ( 38 ) for the window insert have openings for the passage of the measuring volume,
the coupling radiation passes through the windows ( 40 ), ( 42 ) several times, transmitted coupling radiation and remission from optoelectronic receivers located in the absorption and reflectance module ( 18 ), ( 17 ) are measured backwards to the coupling radiation, the window ( 40 ) additionally with radiation of a defined wavelength and the specularly reflected intensity from the interface window ( 40 ) l measurement volume can be measured with a further receiver located in the refraction module ( 15 ), through the windows ( 41 ), ( 43 ) the 90 ° fluorescence and / or 90 ° scatter can be measured by this radiation after passing through these windows a mirror ( 44 ), ( 45 ), optical waveguide ( 48 ), ( 49 ), mirror ( 50 ), ( 51 ), filter in the inserts ( 29 ), ( 30 ) and optoelectronic receivers ( 35 ), ( 36 ). 6. The device according to claim 5, characterized in that the two openings ( 39 ) are provided in the window insert for flowing through the measuring volume with special screens that let the measuring volume pass and block disturbing ambient light. 7. The device according to claim 5, characterized in that the two openings ( 39 ) are provided in the window insert for flowing through the measuring volume with pipe adapters, which are used to connect the probe to the pipe or hose. 8. The device according to claim 5, characterized in that the measuring volume determining element ( 28 ) is designed as a sample carrier insert which can be mounted on a sleeve-shaped, adapted to the jacket shape of the cylinder end part and via the two openings ( 23 ), ( 24 ) in the cylinder jacket in the cylinder can be inserted, this end part being designed as a base for the sample carrier insert and the end part opposite this as a cover, and protective elements being arranged on the sample carrier for protecting the sensor head, reflection module and 90 ° module. 9. Device according to claims 1 and 5, characterized in that that the coupling mirror plane and the counter mirror plane are aligned parallel to each other - are, the optical axes of the opposing and coupling mirror only in the vertical direction tion have a non-zero distance, and both mirrors in a defined Distance from each other are localized by the end faces of the sensor's optical fibers between the single and double focal length of the mirror and the images of the End faces after the first reflection of the coupling radiation at the counter mirror at one Mirror distance of twice the focal length on the bottom, the fiber optic end  opposite areas of the coupling mirror are localized. 10. Device according to claims 1 and 5, characterized in that that instead of the reflection module, a radiation trap is arranged, with Meßvo lumina with pronounced minima and maxima of the absorption one at the wavelength of an absorption maximum and the other at the wavelength of an absorption minimum is used so that the measured in the absorption maximum Remission is a measure of the quotient of the scattering coefficient and the total absorption coefficient ten and in the absorption minimum is a measure of the scattering coefficient, and by the Combination of both sizes absorption and scattering can be determined separately. 11. The device according to claims 1 and 5, characterized in that that in the 90 ° position spatially resolving optical receivers are arranged, which the Size of the radiating surface of the measuring volume from the scattering and / or facing it of fluorescence, this quantity is determined as an inverse measure of the total absorption coefficient is used, the intensity of the lateral scattering and fluorescence for Detection of the scattering and fluorescence properties is measured or not. 12. Device according to claims 1 and 5, characterized in that that for determining the speed of flowing measurement volumes behind the part transmissive coupling mirror localized optoelectronic receivers through this Mirror transmitted coupling radiation registered as frequency meter.