Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
  • G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
  • G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
  • B01L3/00—Containers or dishes for laboratory use, e.g. laboratory glassware; Droppers
  • B01L3/50—Containers for the purpose of retaining a material to be analysed, e.g. test tubes
  • B01L3/508—Containers for the purpose of retaining a material to be analysed, e.g. test tubes rigid containers not provided for above
  • B01L3/5085—Containers for the purpose of retaining a material to be analysed, e.g. test tubes rigid containers not provided for above for multiple samples, e.g. microtitration plates
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/01—Arrangements or apparatus for facilitating the optical investigation
  • G01N21/03—Cuvette constructions
  • G01N21/0303—Optical path conditioning in cuvettes, e.g. windows; adapted optical elements or systems; path modifying or adjustment
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
  • G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
  • G01N21/251—Colorimeters; Construction thereof
  • G01N21/253—Colorimeters; Construction thereof for batch operation, i.e. multisample apparatus
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
  • G01N21/47—Scattering, i.e. diffuse reflection
  • G01N21/49—Scattering, i.e. diffuse reflection within a body or fluid
  • G01N21/51—Scattering, i.e. diffuse reflection within a body or fluid inside a container, e.g. in an ampoule
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
  • B01L2300/00—Additional constructional details
  • B01L2300/06—Auxiliary integrated devices, integrated components
  • B01L2300/0627—Sensor or part of a sensor is integrated
  • B01L2300/0654—Lenses; Optical fibres
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
  • B01L2300/00—Additional constructional details
  • B01L2300/08—Geometry, shape and general structure
  • B01L2300/0809—Geometry, shape and general structure rectangular shaped
  • B01L2300/0829—Multi-well plates; Microtitration plates
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
  • B01L2300/00—Additional constructional details
  • B01L2300/08—Geometry, shape and general structure
  • B01L2300/0832—Geometry, shape and general structure cylindrical, tube shaped
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
  • B01L2300/00—Additional constructional details
  • B01L2300/16—Surface properties and coatings
  • B01L2300/168—Specific optical properties, e.g. reflective coatings
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/01—Arrangements or apparatus for facilitating the optical investigation
  • G01N21/03—Cuvette constructions
  • G01N2021/0389—Windows
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N2201/00—Features of devices classified in G01N21/00
  • G01N2201/06—Illumination; Optics
  • G01N2201/062—LED's
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N2201/00—Features of devices classified in G01N21/00
  • G01N2201/06—Illumination; Optics
  • G01N2201/062—LED's
  • G01N2201/0627—Use of several LED's for spectral resolution
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N2201/00—Features of devices classified in G01N21/00
  • G01N2201/06—Illumination; Optics
  • G01N2201/063—Illuminating optical parts
  • G01N2201/0633—Directed, collimated illumination

Definitions

• the invention relates to an optical measuring unit for obtaining measurement signals from liquid media, which are accommodated in cuvettes lined up with one another, with a light supply unit for emitting incident radiation into the cuvettes, and with a detection unit for detecting one from the cuvettes
• the invention relates to an optical measuring method for
• optical measuring units for obtaining measurement signals from liquid media different types of measurement are used:
• the physical effect underlying the photometric measurement is the absorption of light of specific wavelengths by certain substances present in a liquid.
• the consequent reduction of the intensity of the light passing through the cuvette is detected metrologically and allows a quantitative determination of the concentration of a substance using the following equations:
• the molar concentration c can thus be calculated directly from the result of an extinction or transmission measurement. This type of measurement is used in chemical and enzymatic reactions to determine the
• Molar concentration of certain in the sample blood plasma, urine, etc.
• existing analytes are used.
• light-absorbing substances dyes
• the molar concentration of the analyte to be determined is concluded.
• This type of measurement is used in homogeneous immunoassays where certain analytes, such as metabolites, enzymes, peptides or proteins, are reacted with antibodies. This results in larger structures that cause increased light scattering or turbidity of the reaction mixture.
• the intensity of the continuous light beam attenuates as a result of increasing turbidity
• the intensity of the scattered light beam increases with increasing haze at a detection angle of, for example, 90 °.
• the turbidity measurement in the form of transmission measurement is called turbidimetry.
• the relevant measuring device as a turbidimeter.
• Measuring device as a nephelometer.
• liquid medium
• analysis sample (usually only called sample or substance sample) is called the entirety of the material to be examined.
• Analytes are those substances contained in a sample, on which a statement in a chemical analysis, for example about their
• a reagent is a substance that shows a specific reaction on contact with certain other substances present in a sample.
• the addition of a reagent to a sample leads to a chemical reaction with the formation of a characteristic color change, which allows conclusions to be drawn about the presence or absence and the molar concentration of certain analytes in the sample.
• a cuvette in the sense of the present invention denotes an all-round
• a cuvette in the sense of the present invention has at least one window which is permeable to the applied optical measuring method and is arranged in a side wall of the cuvette or is entirely optically transparent.
• stationary cuvette array :
• optical elements for generating as parallel a beam path as possible. Basically, the light of a more or less punctiform source is transformed into a parallel bundle of rays.
• Optical elements that align the light emanating from an LED substantially parallel for example, converging lenses, TIR lenses, parabolic mirrors, and aperture arrangements.
• optical elements for filtering
• optical components in particular interference filters, for the transmitted light wavelength-dependent or frequency-dependent, i.
• these components are constructed as dielectric layers on a thin carrier. Since the wavelength-dependent transmittance depends on the angle of incidence of the light, it is advantageous if the light rays incident on the filter element run as parallel as possible and are aligned parallel to the optical axis.
• Bandsafe filters longpass filters, shortpass filters, bandpass filters and dichroic interference filters are used. Particularly preferred are bandpass filters because they have a high transmittance for a particular wavelength band while absorbing shorter or longer wavelengths.
• Reaction vessels 24 immersed in a temperature bath 25 which is filled with water 26 of constant temperature.
• a fixed in the temperature bath 25 arranged photometer 27 has an LED light source 28, the light by means of a
• Condenser lens 29 and a deflection mirror 30 is irradiated in the present in the reaction vessel 24 sample 31.
• a light source a semiconductor laser can also be used.
• a photodetector 32 of the photometer 27 is arranged on the opposite side of the reaction vessel 24 .
• apertures 34 are provided for the inlet and outlet radiation in the measuring position 33 of the photometer.
• US 2013/0301051 A1 (Pogosyan) describes a cost-effective, portable photometer which-as illustrated in FIG. 1b of the present application-has as light sources 35 several LEDs with different wavelengths and as detector 36 a photodiode or a photomultiplier.
• the photometer can be used to examine chemical, biological or pharmaceutical samples which are located in a sample holder 37 between the light sources 35 and the detector 36.
• the light of the light sources 35 is - possibly after the passage of an interference filter 38 - directed to a light-scattering surface 39 and passes through a collimator lens 40 and a slit 41 in the Sample holder 37 present sample.
• the detector 36 may be pivoted from a first position to a second position.
• a collimator lens functions optimally if the scattering surface is chosen to be very small, more or less punctiform, which, however, reduces the luminous efficacy.
• Detector array arranged. In the case of a rotational movement of the cuvettes C in the direction of the arrow, the optical beam paths are crossed and the samples in the cuvettes C can be successively exposed to the light of the different wavelengths A 1 to L 5.
• the AT 510 631 Bl claims a spectrometer with multiple LEDs as the light source 44, as shown in Fig. Id of the subject application.
• the spectrometer is used to examine the ingredients of a fluid 42, by means of the light source 44 and a detector 45, the light of the light source 44 is guided with a predetermined spectral range through an entrance window 47 through the fluid to be examined 42 and through an exit window 48 to the detector 45 ,
• the light source 44 is formed by a plurality of arranged in a holder 50, connected to a control electronics 43 LEDs 49, which are designed to emit light of different wavelength ranges within the predetermined spectral range.
• the control electronics 43 is designed for the sequential activation of the light-emitting diodes 49, wherein a compensation detector 51 connected to the control electronics 43 is arranged in the holder 50 in relation to the light-emitting diodes 49. In the beam path between the
• examining fluid can be arranged transversely to the measuring radiation, a further detector 54.
• WO 2010/122203 A1 discloses a photometer based on an array of multiple LEDs as a light source for measuring the absorption and turbidity of a sample present in a cuvette.
• the light from the individual LEDs is coupled into the beam path in front of the sample by means of a beam splitter and bandpass filter.
• a reference photodiode is further arranged on the side of the light source.
• a photodiode is arranged in the beam path after the sample, on the detection side.
• the individual cuvettes are guided past the photometer.
• the light source is very complex and consists of many individual components.
• the light of the LEDs must be further from the Cuvette are removed, several beam splitters happen, resulting in loss of intensity.
• a rotor Concentric with a cuvette hub, a rotor is arranged, are arranged on the mutually fixedly positioned pairs of light sources and photodetectors. With appropriate positioning or rotation, the individual cuvettes come to rest between the light source and the photodetector.
• a single light source is centrally positioned on the axis of rotation and the photodetectors are located (seen in the radial direction) on the opposite side of the cuvettes.
• the cuvette turntable rotates only slowly, the rotor performs a much faster rotation with the light source, which leads to a significant increase in the measurement frequency.
• the rotor may have a filter wheel with different filters, which can be brought into the beam path between the central light source and the cuvette. However, the rotor must stop at each cuvette, after which the respective filter is selected by rotation of the filter wheel.
• the rotatable device which carries the light source in the form of an LED and the photodetector in the form of a photodiode, be arranged below the receptacle of the sample vessels, whereby it is always possible to access the sample vessels by means of a gripping arm.
• the rotatable device may also include multiple LEDs of different wavelengths and multiple photodiodes to allow the samples to be measured at multiple wavelengths.
• the photodiodes may be replaced by a CCD element.
• the object of the invention is to provide an optical measuring unit and an optical
• Measuring methods for obtaining measurement signals from liquid media which are housed in cuvettes juxtaposed to improve so that in the course of the chemical reactions in the individual cuvettes and in a short time sequence, a plurality of measurements at different wavelengths can be performed, the kinematic Cost, due to translational and / or rotational relative movements between individual components of the measuring system, should be reduced as possible.
• An optical measuring unit for obtaining measurement signals from liquid media, which are accommodated in cuvettes arranged side by side, each cuvette being equipped with a lateral entrance window and at least one lateral exit window, has the following components: a light supply unit which is suitable for spectrally different time series To emit incident radiation into the entrance window of each cuvette, the light providing unit having a plurality of LED light sources emitting spectrally different spectrally in the UV / VIS / NIR wavelength range, and a detection unit which is suitable for one of the at least one
• Cuvette arrays is assigned at least one photodiode fixed.
• the cuvettes are arranged as immovable, stationary cuvette array, each cuvette having its individual detectors (transmitted light detector (for photometric and turbidimetric measurements) and / or scattered-light detector (for nephelometric measurements)) permanently assigned to it and that from the individual Cuvettes leaking light - so also any detectors (transmitted light detector (for photometric and turbidimetric measurements) and / or scattered-light detector (for nephelometric measurements)) permanently assigned to it and that from the individual Cuvettes leaking light - so also any
• the light distribution device has a cavity whose inner surfaces are at least partially mirrored and / or designed to be reflective, and wherein the light distribution device for each LED light source has an inlet opening for feeding the light into the cavity and wherein the light distribution device for each cuvette of
• Cuvettearrays having an outlet opening for feeding the light into the cuvette. This is a compact, cost-effective variant, since the light distribution device, the multiple LED light sources different
• Wavelength, stationary associated with a number of cuvettes.
• the stationary stationary In cuvette arrays with a large number of cuvettes, the stationary
• Light distribution device is assigned permanently. Overall, therefore, an optical measuring unit is realized which has no moving components.
• the light is the
• Inlets of the LED light sources opposite, inner surface of the light distribution device preferably wavy and reflective designed.
• the inner surface of the cuvettes facing the outlet openings is
• Light distribution device designed diffuse reflective.
• Light providing unit at least one-dimensional, rod-shaped
• a light source array having a plurality of LED light sources aligned along the stationary cuvette array and movable along the stationary cuvette array such that each cuvette of the stationary cuvette array is assignable to each LED light source of the light source array.
• Cuvette arrays of movable, rod-shaped light source arrays by a cost-effective production (only one light source array for a variety of
• the LED light sources of the light providing unit are arranged as a 2D LED array, each cuvette of the stationary cuvette array is assigned a fixed 2D LED array fixed.
• each cuvette has an individual photometer, comprising a permanently assigned 2D LED array as light source and a fixedly assigned photodiode as detector.
• a saving variant for the third variant is characterized in that the light providing unit - similar to the third variant is designed as a 2D LED array, which - similar to the second variant along the
• stationary cell arrays is designed to be movable. In order to further increase the measurement frequency on individual cuvettes with long cuvette arrays, it is also possible for a plurality of 2D LED arrays to be arranged along individual segments of the stationary cell
• This fourth variant is more cost-effective than the third variant in that a 2D LED array is not required for each cuvette.
• An inventive optical measuring method for obtaining measurement signals from liquid media in particular in connection with the first
• Embodiment of the invention characterized by the following steps:
• the measuring radiation emerging from the cuvettes is converted into an electrical measuring signal and displayed in a display unit after appropriate preparation.
• Measuring unit for obtaining measurement signals from liquid media in a three-dimensional view, looking towards the
• Light providing unit, 2b shows the embodiment according to FIG. 2a in a three-dimensional view, looking in the direction of the detection unit, FIG.
• FIG. 3a is a sectional view of the light providing unit according to FIG. 2a along the line II-II in FIG. 3b, FIG.
• FIG. 3b is a sectional view of the light providing unit of FIG. 2a along line III-III in Fig. 3a,
• Fig. 3c is a three-dimensional detail of a tube body of the
• FIG. 3d shows an enlarged detailed view from FIG. 3a, FIG.
• FIG. 3e shows a variant of the light providing unit in a sectional illustration according to FIG. 3a
• 3g to 3i show three different detail variants of the beam guidance on the input and output side of a cuvette in a sectional view according to FIG. 3f, FIG.
• Fig. 4 is a block diagram for the electronic control of the optical
• 5a shows a first diagram to illustrate a measuring procedure (modes 1 and 2)
• 5b shows a second diagram to illustrate a measurement procedure (mode 3)
• 6a a second embodiment of an optical measuring unit according to the invention for obtaining measurement signals from liquid media in a three-dimensional view
• 6b is an enlarged sectional view through the axis of a cuvette
• FIG. 7a shows a third embodiment of an optical measuring unit according to the invention for obtaining measurement signals from liquid media in a three-dimensional view
• FIG. 7c is an enlarged detail view of Fig. 7a.
• the optical measuring devices illustrated in FIGS. 1 a to 1 d concern examples of the prior art and have already been described above
• the embodiments of the optical measuring unit 500 according to the invention described below for obtaining measurement signals from liquid media, which are accommodated in cuvettes 201 of a stationary (ie stationary) cuvette array 200, have the following basic elements: a light supply unit 540 for emitting incident radiation into the cuvette Cuvettes 201 of the cuvette array 200, wherein the light supply unit 540 has a plurality of differently emitted in the UV / VIS / NIR wavelength range LED light sources 541, and a detection unit 550 for detecting one of the cuvettes 201 of
• Cuvette arrays 200 exiting measuring radiation and conversion of
• the detection unit 550 is designed so that each cuvette 201 of the cuvette array 200 at least one photodiode 551 is assigned fixed and stationary.
• Embodiment variant of the optical measuring unit 500 according to the invention has at least one stationary light distribution device 542 which distributes the light of the individual LED light sources 541 to the individual cuvettes 201 of the stationary cuvette array 200.
• the cuvettes 201 are rectilinear, i. linear, arranged, but deviating would also be
• the light distribution device 542 has a cavity formed by walls, the inner surfaces 543, 544, 545, as well as the rear wall and the two
• End surfaces at least partially mirrored and / or diffusely reflective
• the light distributor device 542 has, for each LED light source 541 in the bottom surface 545, an inlet opening 546 for feeding the light into the cavity and has for each cuvette 201 of the cuvette array 200 an outlet opening 547 for feeding the light into the cuvette 201.
• the inlet 546 of the LED light sources 541 opposite, inner surface 544 on the top surface of the
• Light distribution device 542 wavy and reflective carried out, wherein the waves of the corrugated inner surface 544 preferably normal to the longitudinal extent of
• Light distribution device 542 are aligned to that of the individual LED Light sources 541 optimally distributed in the longitudinal direction of the light distribution device 542 (see Fig. 3b).
• Entry window 202 of the cuvette 201 is suitable for example barium sulfate
• At least individual LED light sources 541 of the light providing unit 540 for improving the spectral characteristic and for feeding the light into the light distribution means 542 have optical filters, such as color filters or interference filters.
• optical filters such as color filters or interference filters.
• at least one optical element for collimating the light is arranged in the light path on the input side of the interference filter 553.
• the LED light source 541 may comprise an LED 548 arranged in a TIR lens 549, a tube body 552 for eliminating non-parallel beam portions of the LED, and an entrance side into the light distribution device 542 a narrow-band filter, preferably a
• Interference filter 553 have.
• the radiation emerging from the interference filter 553 (essentially monochromatic light) is intended to be a
• predetermined bandwidth having a preferred half-width of less than or equal to 10 nanometers, centered at a predetermined wavelength.
• the tube body 552 parallel to the longitudinal axis of the LED light source 541 extending, elongated through-holes 570 have, the walls 571 consist of a light-absorbing material or coated with such a material (see the detailed illustration of FIG. 3c). It thus reach - within a certain tolerance - only parallel aligned rays on the interference filter 553, as deviating rays are absorbed by the tube body 552.
• Bottom surface 545 of the light distribution device 542 are arranged, is shown in the sectional views of FIG. 3e and 3f.
• a converging lens 590 is arranged, which aligns the light emitted by an LED 548 in parallel for entry into the interference filter 553, the output side of the interference filter 553 a
• Light distribution device 542 radiation may be arranged.
• the light beams are preferably fanned out to such an extent (see marginal rays Si, S 2 in FIG. 3 f) that the inner surfaces of the light distribution device 542 are illuminated as homogeneously as possible.
• the surface 544 lying opposite the bottom surface 545 is particularly preferably illuminated over as large an area as possible, while the lateral surface 543 is not exposed directly.
• the light rays exit conically, whereby the surface 544 of the light distributor device directly opposite the LED light source 541 is exposed in a substantially circular manner (see FIG. 3f, second LED light source from the left, edge jets S 3 , S 4 ).
• FIG. 3f second LED light source from the left, edge jets S 3 , S 4 .
• Light distribution device 542 to emerge, as homogeneous a possible illumination of the entire surface 544 by means of an aspherical scattering lens 591 is advantageous (see Fig. 3f, first LED light source from the left, marginal rays Si, S 2 ).
• the LED light source 541 on the far right in the illustration according to FIG. 3 f has no
• photodiodes 551 of the detection unit 550 on the input side of the entrance window 202 and on the exit side of the exit window 203 of each cuvette 201 are channel-like passages 578 in the wall of the cell
• Light distribution device 542 cuvette inlet radiation emerging as well as unwanted radiation components U 2 emerging from the cuvette 201
• Cell receptacle 578 according to a variant shown in Fig. 3i as a channel 594 smooth surface, be designed with a smaller diameter in relation to the length of the bore and thereby hide the unwanted radiation components Ui, U 2 on the way to the photodiode 551.
• the channel-like feedthrough 578 according to FIG. 3h can have an exemption 593 or a cavity in which the unwanted radiation components Ui, U 2 run dead.
• Bushings 578 according to FIG. 3g have a grooved or serrated structure 592, on which unwanted radiation components Ui, U 2 , which is too large Angular deviation from the beam axis have blocked or absorbed.
• This variant can be cost effective in a single, above all
• Grooved structure 592 can be realized by means of threaded holes.
• the light guidance or light guidance in the optical measuring unit takes place in several steps in order to meet the requirements:
• the spatially broadly emitted light of the LEDs 548 is collected by means of optical lenses, TIR lenses 549 or parabolic mirrors, parallelized and directed in the direction of the interior of the light distribution device 542.
• the LED 548 may also be arranged in the focal point of the converging lens 590, which aligns the light of the LED 548 as parallel as possible.
• the further progression of insufficiently parallelized portions of the light can be prevented.
• optical bandpass filters such as interference filters 553, are provided to obtain a predetermined, narrowband, monochromatic light.
• the interference filter 553 may be followed by a diverging lens 591 in order to emit those exiting from the interference filter 553
• the substantially parallelepiped light distributor device 542 is configured in such a way that the outlet openings 547 have a diffuse one reflective surface 543 is arranged and with the exception of the inlet and outlet openings, the remaining inner surfaces have diffusely reflecting and / or reflecting surfaces.
• the cover surface has a corrugated structure 544 (see FIG. 3 b), while the remaining inner surfaces are preferably flat, so that light is scattered or reflected as effectively as possible over a spectral range of approximately 340 to 800 nm.
• the outlet openings 547 are arranged, through which the light can pass directly to the entrance windows 202 of the cuvettes 201.
• Interposition of a diaphragm between the light distribution device 542 and the cuvette 201 generates a beam directed into the interior of the cuvette 201.
• the measuring radiation is directed from the exit window 203 of the cuvette 201, if necessary with the interposition of an aperture, to the photodiode 551 of the detection unit 550.
• the light distribution device 542 on the output side of in a wall, for example, the rear wall, the light distribution device 542 arranged through holes or pinholes 576 monitor or
• Reference detectors 575 arranged with which fluctuations of the measuring radiation can be detected at any time.
• Each cuvette 201 may be assigned a pinhole plate 576 together with a reference detector 575. If each cuvette 201 a
• Reference photodiode is assigned, these are preferably at the
• Reference detectors 575 provided (see Fig. 2a).
• the stationary cuvette array 200 may be
• each segment 210 is assigned a separate light providing unit 540 fixed.
• Each segment 210 is associated with a common, over the entire length of the segment extending light distribution device 542, which via a
• n of mounting positions for LED light sources 541 for up to, for example, 16 optical channels with light of different wavelengths (l ⁇ to lh) has.
• the individual LEDs of the LED light sources 541 may preferably be arranged in the form of an LED array on a common printed circuit board 582, for example made of aluminum. Adjacent installation positions (see Fig. 2a) may be equipped to increase the intensity of LED light sources same Wellenläge. In the area of the front, the light distribution device 542 adjacent
• the light distributor 542 has a circular opening, the so-called outlet opening 547, through which the light generated by the LEDs is irradiated through the entrance window 202 into the interior of the cuvette 201.
• the feedthrough 578 in the cuvette receptacle 579, between the outlet opening 547 and the entrance window 202 into the cuvette 201, according to FIG. 3d, can also have a funnel-shaped design and optionally diaphragms
• the optical feedthroughs 578 in the cuvette receptacle 579 can thus be funnel-shaped (FIG. 3d) independently of one another on both sides of the inlet 202 and exit windows 203 of the cuvette 201, as a smooth-surfaced channel 594 (FIG. 3i) with a grooved or toothed structure 592 ( Figure 3g) or with in the channel
• Cell receptacle 579 made of a light-absorbing material or are coated with such.
• the light of each optical channel of the LED light sources 541 passes through the circular
• the measurement of the intensity I of the light transmitted through the cuvettes 201 takes place by means of a stationary array of photodiodes 551 (at least one
• Light distribution device 542 facing away exit window 203 of the cuvettes 201 are placed.
• a second photodiode may be arranged on each cuvette 201 in an angle rotated by 90 °, for example, from the continuous beam path for carrying out nephelometric scattered light measurements.
• a solid aluminum block 583 for example with the aid of Peltier components tempered (cooling and heating possibility) attached to the circuit board 582 of the LED light sources 541.
• the electronics shown schematically in FIG. 4 for the optical measuring unit 500 consists of a plurality of circuit units, which are distributed over a plurality of printed circuit boards and corresponding to their function on the stationary cuvette array 200 (see arrow) are geometrically placed.
• the printed circuit board of the transmitting unit 580 contains 16 parallel current sources 581 which are each assigned to a specific light source (LED 548) with a specific wavelength.
• the current sources 581 may be controlled by an optical controller (584) in magnitude and in pulse length, so that a desired current pulse in length and magnitude for the
• Light pulse can be adjusted.
• the LED supply voltage can also be controlled individually for each LED channel.
• the board of the transmitting unit 580 is screwed for the purpose of thermostating with an aluminum block 583 with cooling fins 577 (see Fig. 2a) and by means of Peltier elements to an adjustable Temperature, for example, between 29 ° C and 41 ° C, regulated.
• the thermal drift of the current sources 581 can thereby be reduced to a minimum.
• the power loss occurring in the current sources 581 is determined by the time
• Current source 581 activated per unit of time, thus always only light with a certain predetermined wavelength is generated.
• the actual light sources are realized on a separate, cooled aluminum circuit board 582 by means of, for example, 16 selected LEDs 548 having the desired 16 wavelengths.
• the aluminum circuit board 582 is for the better
• the LEDs used thermal coupling of the LEDs used, screwed to the aluminum block 583 and thus also at a constant temperature (for example, + 37 ° C) operated.
• a constant temperature for example, + 37 ° C
• the LEDs have a constant average temperature and thus produce a low spectral shift.
• the aluminum circuit board or board 582 with the LEDs is directly on the
• Light distribution device 542 (see Fig. 2a) arranged to best possible
• the light of the LEDs 548 is first aligned in parallel via TIR lenses 549 and tube body 552, then spectrally filtered via optical filters 553 and then evenly distributed in the interior of the light distribution device 542 so that the light on 16 adjacent outlet openings 547 to the 16th
• Another circuit board 585 is equipped with up to 16 monitor or reference photodiodes 575 which detect the light generated by the LEDs 548 prior to passage of the respective cuvette.
• monitor or reference photodiodes 575 only two global monitor or reference photodiodes 575 can be used. In this case, the light is not directly in front of each cuvette but in several, suitable places of
• Light distribution device 542 measured. Due to the constant geometric conditions, the light in front of each cuvette can be converted using a geometry factor.
• This circuit board contains one of the number of
• Cuvettes in the segment 210 of the cuvette array 200 corresponding number of photodiodes 551 (16 photodiodes in the example shown) for the light emitted from the cuvettes 201 transmitted light.
• the detector unit processes per cuvette two analog values of the two associated photodiodes 551, 575 of transmitted light and
• a third analog value can be detected by each cuvette by means of a laterally arranged photodiode, the signal path of which, however, being shown in FIG.
• the two signal paths starting from the photodiodes 551, 575 are processed synchronously by two 16: 1 multiplexers 587, inverters, integrators and ADCs and converted into a digital measured value.
• Multiplexers 587 allow the selection, for example, of 16 cuvette channels, and to switch sequentially in a configurable sequence.
• the cuvette 201 experiences light attenuation of several decades.
• the photodiodes 551 are usually operated in the lowest control range just above the dark value.
• the resulting very low photocurrents have a high sensitivity to electrical noise of all kinds. Therefore, it is essential that the photodiode (photocurrent) signal be amplified in close proximity to the detector, the photosensitive layer, and that both the power supply and the layout of the circuit be optimized for electrical noise.
• the preferred arrangement has one on a single circuit board 586
• present compact circuit with multiple, spaced apart the cuvettes 201 of the cuvette array 200 photodiodes 551 of the detection unit 550 with immediately following the electrical outputs of the individual photodiodes 551 following preamplifiers 589 (preferably transimpedance amplifiers), subsequent low pass filters, multiplexer, integrator and 24 bit ADCs.
• preamplifiers 589 preferably transimpedance amplifiers
• subsequent low pass filters preferably transimpedance amplifiers
• multiplexer preferably transimpedance amplifiers
• integrator integrator
• 24 bit ADCs particularly preferred are photodiodes 551 with a transimpedance amplifier integrated in the housing of the photodiode.
• each segment 210 is assigned a separate light distribution device 542 fixedly (see FIGS. 2 a / b)
• additional circuit boards indicated by dashed lines are provided at the transmission unit 580, the circuit board for the LEDs 582, the circuit board for the monitor - respectively.
• the central circuit board 584 for the optical measuring unit 500 is equipped with the optical controller.
• the optical control unit is realized by a programmable logic (FPGA) as a state machine and at the same time the transmitting unit 580 and operate the detector unit 586.
• FPGA programmable logic
• the individual light measurements are broken down into light and dark measurements and can be parameterized differently line by line in a configuration memory.
• the state machine processes these configuration lines in sequence, whereby lines can also be skipped.
• the distinction for light and dark measurement is defined by a flag in the configuration line, as well as the desired cuvette channel and light source. Furthermore, in the configuration line, the desired delay settings, amperage and
• Pulse length the selection of the reference photodiode, the LED supply voltage, the oversampling and averaging default and the
• the detector unit 586 is driven synchronized to the transmitting unit 580 and can be set by global parameters with averaging or oversampling settings. Furthermore, the desired integration time is read out of the configuration line with which the light signal is to be integrated. Likewise, the delay time for the integrator and the integration slope can be selected here by means of global parameters, so that the settling times of the measurement signal and the integration speed can be switched over.
• the analog measured value is thus selected from the corresponding photodiode 551 with transimpedance amplifier via the multiplexer 587 and measured by means of inverter and integrator and optional logarithmic amplifier and digitized with a high-resolution ADC measurements with or without oversampling. Ultimately - if a scattered light measurement takes place - three
• Analog measured values (transmitted light, monitor or reference light, scattered light) digitized simultaneously with three ADCs and stored as raw measured values in the internal memory line by line. It is essential that the measurement of transmitted light and monitor or
• the internal memory contains all raw data and is cyclically read by the evaluation processor by software and converted by a conversion algorithm into a final measured value.
• the conversion takes into account the dark value and light value as well as the Io measurement and Ii measurement before and after mixing in of the reagents.
• the temporal change of the measured values can also be detected by successive measurements. It is essential that the measurements are periodic and give a repeatable measurement cycle in accordance with the set period.
• the calculated data are packaged per cuvette into defined data packets and transmitted to the main computer 588 by means of a local Ethernet interface.
• a local Ethernet interface As a result of this data reduction, it is possible to process all cuvettes of the cuvette array 200 of the optical measuring unit 500 and to transfer them to the main computer 588.
• the measurement of I or Io in rapid succession for each cuvette with a high sampling frequency (> lHz) is possible.
• Detection unit 500 to control or read.
• the periodic drive signal of the individual LED light sources 541 is determined in terms of pulse and integration duration and the current level used for each combination of cuvette and wavelength for the measurement mode used and not changed during operation.
• the control of 16 LED light sources 541 takes place via 16 separate current sources 581 and their environment hardware.
• the exposure of each cuvette to each spectral channel of the LED light sources 541 and the integration times used are individually defined (16 x 16 combinations).
• the individual LEDs emit (or in individual positions to increase the intensity also several LEDs) in the course of a measurement cycle in sequential
• Sequence one light pulse which is repeatedly reflected in the interior of the light distribution device 542 on the inner walls and finally passes through the 16 outlet openings 547 to the 16 associated cuvettes 201 (see Fig. 3a).
• the measurement is done individually for each combination of cuvette and wavelength, whereby in modes 1 and 2 a light pulse is generated for each measurement point.
• the spectral channels (l ⁇ ... l16) of the individual LED light sources 541 are activated and deactivated in a fixed order.
• the resulting light flashes are detected and measured by the photodiode 551 selected by the multiplexer 587.
• the sensors After passing through all the spectral channels, the sensors are moved from the cuvette position K1 to the
• the measuring method according to modes 1 and 2 is thus characterized in that the spectral channels l ⁇ ... lh the individual LED light sources 541 in one
• the LED light sources 541 are switched in a different order than in modes 1 and 2, respectively.
• Each LED light source 541 or each spectral channel is in the cycle (indicated by the dotted line) only turned on once and then measured all 16 cuvettes in a row, with no dark measurement between these individual measurements.
• the first cuvette Kl comes with a delay
• the other cuvettes K2 to K16 can be measured faster without additional settling time.
• each LED is turned on only once, measuring all 16 cuvettes at a time. If a dark measurement is required, a dark value is measured once, for example at the beginning or end of the cycle for the measurement of the 16 cuvettes.
• Cuvette positions require 16 x 16 light measurements. Adding the 16 dark measurements (once per cycle) gives 272 individual measurements.
• the measuring method according to mode 3 is therefore characterized in that the spectral channel AI of the first LED light sources 541 is activated, wherein in a predetermined order the photodiodes 551 arranged in the cuvette positions Kl ... Km are detected, wherein after the passage of all
• Mode 3 is faster overall than the 512 alternately running modes
• the light supply unit 540 has at least one one-dimensional, rod-shaped light source array 554 with a plurality of LED light sources 541 aligned along the stationary cuvette array 200, for example an analytical device is and is designed movable along the stationary cuvette array 200.
• Each cuvette 201 of the stationary cuvette array 200 can thus each LED light source 541 of
• Light source arrays 554 are assigned.
• an LED light source 541 is preferably arranged together with a beam splitter 555 and a reference detector 556 in a common, for example tubular, housing 560.
• Light paths of the individual juxtaposed LED light source 541 can be separated thereby.
• Individual LED light sources 541 of the rod-shaped light source array 554 may have a narrow-band filter 558 for injecting the light into the cuvettes 201, optical elements 557 for collimating and improving the spectral characteristic of the light. Furthermore, a condenser, preferably a
• Conveying lens 559 be provided for focusing the light in the cuvette 201.
• the optical elements 557 for collimation, for filtering 558 and for focusing 559 can be omitted in their entirety or at least partially.
• the individual cuvettes 201 of the stationary cuvette array 200 fix
• Photodiode array on a common board 572 arranged.
• Detecting unit 550 has - starting from each cuvette 201 of the stationary cuvette array 200 - a, for example, tubular receptacle 573, in which - if necessary - optical elements 569 for bundling the
• Measuring radiation on the photodiode 551 and - if necessary - a filter element 574 are arranged.
• Wavelength range of ultraviolet and visible light are performed by the individual LED light sources 541 different wavelengths of the light providing unit 540 are positioned in succession in front of the individual cuvettes 201. Then, in each case, the intensity of the light which has passed through the respective cuvette 202 is then transmitted through the permanently assigned, stationary one
• Detector unit 550 measured. As an alternative to positioning, a measurement is also "on the fly”. in passing possible.
• the third embodiment of the optical measuring unit 500 the LED light sources 541 of the light supply unit 540 are arranged as a 2D LED array 561, each cuvette 201 of the stationary cuvette array 200 is a stationary 2D LED array 561 is fixed.
• the measurement processes can be significantly accelerated by eliminating mechanical movements within the optical measuring unit 500 ,
• the LED light sources 541 may be arranged in the light supply unit 540 as a single 2D LED array 561 (as in the detailed illustration of FIG. 7c), wherein the
• Light supply unit 540 along the entire stationary cuvette array 200 or a segment 210 of the cuvette array 200 is carried out movable (similar to that shown in Fig. 6a), such that each cuvette 201 of
• the 2D LED array 561 can be assigned.
• a light supply unit 540 with a 2D LED array 561 is provided for each segment 210.
• a 2D lens array 562 For feeding the light of the individual LEDs 548 of the 2D LED array 561 into the cuvettes 201, a 2D lens array 562 is provided for collimating the light of the individual LEDs. Furthermore, a 2D filter array 563 for narrow-band filtering of the light is arranged in the beam path for improving the spectral characteristic. The filter array 563 may not have a filter function in individual positions, for example if a narrow-band and parallel emitting laser diode is arranged in this position of the 2D LED array 561.
• At least one condenser preferably one
• Conveying lens 564 for focusing the light in the individual cuvettes 200th
• the 2D LED array 561 consists of LED emitters bonded on a single substrate 565, the 2D lens array 562 being a 2D microlens array and the 2D filter array 563 being a 2D micro-interference filter array.
• one LED light source 541, comprising a 2D LED array 561, a 2D lens array 562, a 2D filter array 563 and a converging lens 564 can preferably be arranged together with a beam splitter 566 and a reference detector 567 in a common housing 568.
• each cuvette 201 has an individual photometer unit consisting of a light supply unit for light with up to 9, 12 or 16 different wavelengths (l ⁇ to lh) which are generated by individual LEDs 548.
• a light supply unit for light with up to 9, 12 or 16 different wavelengths (l ⁇ to lh) which are generated by individual LEDs 548.
• LEDs 548 When using commercial LEDs (side length about 2 mm and a distance of about 0.5 mm) which are soldered by means of push-through mounting on a board, is in a 4 x 4 array with an area of about 10 x 10 mm 2 to count.
• the semiconductors of the individual LEDs can be implemented in a space-saving area of less than 5 ⁇ 5 mm 2 .
• the LED chips are preferably bonded directly to a highly thermally conductive aluminum circuit board.
• edge length of 300 to 900 pm and a distance of about 100 pm for example, 16 LED chips can be accommodated on a square surface of 1.6 to 4 mm edge length. Accordingly, the individual show
• the LED chips may be placed on the 2D array in columns or rows, e.g. 3 x 3, 3 x 4 or 4 x 4, or be arranged in concentric circles.
• the detection unit 550 has, starting from each cuvette 201 of the stationary cuvette array 200, a tubular receptacle 573, for example, in which optical elements 569 for focusing the measuring radiation onto the photodiode 551 and if necessary - a filter element 574 are arranged.
• the individual cuvettes 201 permanently assigned photodiodes 551 of the detection unit 550 are preferably arranged as a photodiode array on a common board 572.

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• 2019
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