MMS â Monolithic M i n i a t u re - S p e c t ro m e t e r - Photon Lines

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ApplicationsThe flexible design of the <strong>MMS</strong> makes it suitablefor use in many applications. They can beclassified according to the measu<strong>re</strong>ment principlesused, the fields of use or the materials to beanalyzed. The <strong>MMS</strong> modules using cro s s - s e c t i o nc o n v e rters as optical inputs offer specific benefitsin practical work. lt is very easy to connectother fib<strong>re</strong>s using the SMA connector.In addition, the round input offers considerablybetter conditions for most illumination situationsthan the classic entrance slit. However, themost important asset of the <strong>MMS</strong> modules istheir compactness, light sensitivity and insensitivityto external influences. This allows them tobe di<strong>re</strong>ctly integrated in processes; for example,the <strong>MMS</strong> modules can be built into printingmachines for the on-line inspection of paper orcolour quality. In most of the applications mentionedin the following, an on-line check is highlyi n t e <strong>re</strong> s t i n g .Measu<strong>re</strong>ment principles1 . E m i s s i o n2 . D i ffuse <strong>re</strong> f l e c t i o n3 . R e f l e c t i o n4 . Tr a n s m i s s i o n – a b s o r p t i o n5 . I n t e rf e <strong>re</strong>nce spectru mE m i s s i o nTo determine the spectral emission of a lights o u rce, part of the light is di<strong>re</strong>cted to the spectrometermodule. In view of the high light sensitivityof the <strong>MMS</strong> modules, it is in many cases sufficientto bring the fib<strong>re</strong> near the light sourc e .For optimization, an (achromatic) collective lenscan be used.Examples■ Checking illuminators (aging)■ D e t e rmining the wavelength of LEDsor (tunable) lasers (see page 9)■ Luminescence, fluo<strong>re</strong> s c e n c e■ Monitoring the solar spectrum, burns,d i s c h a rges or plasma■ D e t e rmining the temperatu<strong>re</strong> T in accord a n c ewith the Wien displacement law. e.g.:3000 K ↔ 966n mRequi<strong>re</strong>mentsThe wavelength accuracy which is very highconsidering the size of the module allows anexact determination of the wavelength of lights o u rces which emit a single line, such as LEDs(calibration), using the sub-pixel <strong>re</strong>solution proce d u <strong>re</strong>. The <strong>MMS</strong> modules a<strong>re</strong> not suitable forthe analysis of emission radiation containingspectrally adjacent lines which a<strong>re</strong> too closetogether (see page 8).λ max x T = 2.8978 x 10 3 m x K18
D i ffuse <strong>re</strong> f l e c t i o nThe diffuse <strong>re</strong>flection of scatte<strong>re</strong>d light (fro mrough surfaces) supplies information on the colourof the surface. Important for this pro c e d u <strong>re</strong> (inaddition to the spectrometer used) is the lights o u rce and the position of the detector (anglewith surface normal). In most cases, a light sourcewith a wide-band emission, e.g. a halogenlamp, is used. He<strong>re</strong>, too, it is often sufficient tobring the input of the cross-section convert e rclose to the colou<strong>re</strong>d surface to be measu<strong>re</strong> dwithout using additional optics.Examples■ Colour measu<strong>re</strong>ment of diff e <strong>re</strong>nts u rfaces (materials), e.g.■ Condition of coatings■ Analysis of paper quality■ D e t e rmination of fat contents in meatand sausages■ D e t e rmination of the humidity content inc e <strong>re</strong>als, food and celluloseRequi<strong>re</strong>mentsThe <strong>MMS</strong> 1 module has been specially designedfor colour measu<strong>re</strong>ment. Its high <strong>re</strong>peatabilityand light intensity combined with moderate spectral<strong>re</strong>solution exactly meet the demands made inthis fie l d .R e f l e c t i o nReflection is the di<strong>re</strong>ctionally <strong>re</strong>flected lightt h rown back from (low-scatter) surfaces. In additionto the sensor, a light source is needed. ltshould be noted, that <strong>re</strong>flectivity is strongly dependenton the angle α. The most simple setupfor measu<strong>re</strong>ments at α = 0° can be obtainedusing a special light guide which supplies thelight and also di<strong>re</strong>cts it to the detector.Examples■ Coatings in general, anti<strong>re</strong>flection coatingsof surfaces using metals or dielectric coatings■ E l i p s o m e t ry■ Plastic identification for <strong>re</strong>cycling and disposalRequi<strong>re</strong>mentsMany <strong>re</strong>flection spectra do not display anymarked stru c t u <strong>re</strong>s. For this <strong>re</strong>ason, high absolutewavelength accuracy is considerably mo<strong>re</strong> importantin many cases than good spectral <strong>re</strong> s o l u t i o n .α = β
Page 4 and 5: The quasi-monolithic principleC o n
Page 8 and 9: Back to the basics: The specificati
Page 10 and 11: lf the maximum of a line is imaged
Page 12 and 13: It should be noted here</st
Page 14 and 15: i n s t ructions. Scattere<
Page 16 and 17: ControlDiode arrayDiode arr a yThe
Page 20 and 21: I n t e rf e rence
Page 22: SpecificationsPast ModulesM o d u l

MMS â Monolithic M i n i a t u re - S p e c t ro m e t e r - Photon Lines

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MMS â Monolithic M i n i a t u re - S p e c t ro m e t e r - Photon Lines