{"id":578,"date":"2016-06-25T09:51:57","date_gmt":"2016-06-25T09:51:57","guid":{"rendered":"http:\/\/wtheiss.com\/wordpress\/?p=578"},"modified":"2021-03-08T14:27:11","modified_gmt":"2021-03-08T14:27:11","slug":"wosp-rt-desktop","status":"publish","type":"post","link":"https:\/\/wtheiss.com\/wordpress\/?p=578","title":{"rendered":"WOSP-RT-DESKTOP"},"content":{"rendered":"<p><a href=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/20210223_202404.jpg\"><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-large wp-image-1651\" src=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/20210223_202404-1024x768.jpg\" alt=\"\" width=\"474\" height=\"356\" srcset=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/20210223_202404-1024x768.jpg 1024w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/20210223_202404-300x225.jpg 300w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/20210223_202404-768x576.jpg 768w\" sizes=\"(max-width: 474px) 100vw, 474px\" \/><\/a><\/p>\n<p>The WOSP RT-DESKTOP spectrometer system records absolute reflectance and transmittance spectra of glass panes or other flat and shiny samples. Measurements are done in a few seconds. A wide range of angles of incidence is possible: 8\u00b0 to almost 80\u00b0 (depends on sample thickness) for reflectance, and 0\u00b0 to almost 80\u00b0 (depends on sample thickness) for transmittance. No reference standard is needed for reflectance. You can record spectra with or without polarizer.<\/p>\n<p>The system consists of<\/p>\n<ul>\n<li>a WOSP-LEDO-P light source (combination of LEDs and halogen light source)<\/li>\n<li>a mobile spectrometer unit (using an Avantes EVO spectrometer) with a field of view which is much smaller than the homogeneous area of the light source.<\/li>\n<li>mechanical accessories that assist you in positioning all components (the prototype shown here has additional stepper motors which allow automatic angle scans \u2013 the motor drive is not yet part of the product).<\/li>\n<\/ul>\n<p>Spectra are recorded in the range 270 \u2026 1050 nm.<\/p>\n<p>You need to provide a flat table (which is not part of the system) and electrical power. The spectrometer connects to a USB port of your computer. \u00a0Alternatively, you can use an ethernet connection.<\/p>\n<h1>How it works<\/h1>\n<p>You can move both the spectrometer unit and the light source on the table, performing the following sequence of actions:<\/p>\n<ul>\n<li>Pointing the field of view of the spectrometer away from the light source (to a dark surface, ideally) you record the dark spectrum, i.e. the detector signals for vanishing light intensity. A suitable black background is provided with the product.<\/li>\n<li>Then you arrange the components opposite to each other so that the full intensity (100%) is recorded:<\/li>\n<\/ul>\n<p style=\"text-align: center;\"><a href=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/100-percent-measurement.png\"><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-large wp-image-1654\" src=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/100-percent-measurement-1024x606.png\" alt=\"\" width=\"474\" height=\"281\" srcset=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/100-percent-measurement-1024x606.png 1024w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/100-percent-measurement-300x178.png 300w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/100-percent-measurement-768x454.png 768w\" sizes=\"(max-width: 474px) 100vw, 474px\" \/><\/a><\/p>\n<ul>\n<li>From now on you can record absolute transmittance and reflectance spectra for various angles of incidence.<\/li>\n<\/ul>\n<p><a href=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/20210301_112942.jpg\"><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-large wp-image-1655\" src=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/20210301_112942-1024x768.jpg\" alt=\"\" width=\"474\" height=\"356\" srcset=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/20210301_112942-1024x768.jpg 1024w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/20210301_112942-300x225.jpg 300w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/20210301_112942-768x576.jpg 768w\" sizes=\"(max-width: 474px) 100vw, 474px\" \/><\/a><\/p>\n<p><a href=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/20210301_112958.jpg\"><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-large wp-image-1656\" src=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/20210301_112958-1024x768.jpg\" alt=\"\" width=\"474\" height=\"356\" srcset=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/20210301_112958-1024x768.jpg 1024w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/20210301_112958-300x225.jpg 300w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/20210301_112958-768x576.jpg 768w\" sizes=\"(max-width: 474px) 100vw, 474px\" \/><\/a><\/p>\n<p>You are not limited to absolute measurements \u2013 if relative measurements are more appropriate for a given problem, you are free to go this way as well.<\/p>\n<p>Once switched on, the system needs about 45 minutes to stabilize. Here is the development of normalized counts over time:<\/p>\n<p><a href=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/warm-up.png\"><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-large wp-image-1657\" src=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/warm-up-1024x900.png\" alt=\"\" width=\"474\" height=\"417\" srcset=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/warm-up-1024x900.png 1024w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/warm-up-300x264.png 300w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/warm-up-768x675.png 768w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/warm-up.png 1455w\" sizes=\"(max-width: 474px) 100vw, 474px\" \/><\/a><\/p>\n<p>However, this does not mean that you cannot do useful measurements in between: A single measurement takes a few seconds only, and a full automatized angle scan (once the stepper drives are available) takes about 1 minute. The drift over 1 minute time is less than 1% after 10 minutes warming up, and less than 0.5% after a warm-up time of 30 minutes:<\/p>\n<p><a href=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/drift_2.png\"><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-large wp-image-1659\" src=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/drift_2-1024x786.png\" alt=\"\" width=\"474\" height=\"364\" srcset=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/drift_2-1024x786.png 1024w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/drift_2-300x230.png 300w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/drift_2-768x590.png 768w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/drift_2.png 1511w\" sizes=\"(max-width: 474px) 100vw, 474px\" \/><\/a> <a href=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/drift_3.png\"><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-large wp-image-1660\" src=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/drift_3-1024x775.png\" alt=\"\" width=\"474\" height=\"359\" srcset=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/drift_3-1024x775.png 1024w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/drift_3-300x227.png 300w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/drift_3-768x581.png 768w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/drift_3.png 1695w\" sizes=\"(max-width: 474px) 100vw, 474px\" \/><\/a><\/p>\n<p>The system is controlled by our CODE-NF software which allows to compute various technical data from measured spectra like color coordinates or integral transmittance and reflectance values. As an option you can upgrade to the full CODE software package which allows to obtain film thickness and optical constant values based on physical modelling.<\/p>\n<p>In order to record high quality spectra the operators need to execute a few commands only \u2013 the system provides a user interface which offers the necessary functions. Both CODE-NF and CODE are very flexible concerning user interfaces and script-driven automations. You can save measured spectra manually or automatically to files in folders or to a MySQL or Microsoft SQL server database.<\/p>\n<h1>Examples<\/h1>\n<p>The measurements shown below have been taken during measurements done on automotive glass coatings (used in a laminate). Samples were provided by C. K\u00f6ckert of VON ARDENNE GmbH\u00a0(thanks a lot!) \u2013 they do not represent a regular coating product but have been generated for product development purposes. The measurement system records a sequence of reflectance spectra, recorded at 8\u00b0, 10\u00b0, 15\u00b0, \u2026, 75\u00b0, 80\u00b0. Spectra and color values are displayed and stored.<\/p>\n<p>Here is a typical sequence of spectra:<\/p>\n<p><a href=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/14297A-Rf-3D.png\"><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-large wp-image-1661\" src=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/14297A-Rf-3D-1024x761.png\" alt=\"\" width=\"474\" height=\"352\" srcset=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/14297A-Rf-3D-1024x761.png 1024w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/14297A-Rf-3D-300x223.png 300w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/14297A-Rf-3D-768x571.png 768w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/14297A-Rf-3D.png 1675w\" sizes=\"(max-width: 474px) 100vw, 474px\" \/><\/a><\/p>\n<p>After the angle scan the system checks for a drift of the light source (100% line) and displays the angle variation of color (a* and b*, in this case):<\/p>\n<p><a href=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/14297A-rf.png\"><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-large wp-image-1662\" src=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/14297A-rf-1024x578.png\" alt=\"\" width=\"474\" height=\"268\" srcset=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/14297A-rf-1024x578.png 1024w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/14297A-rf-300x169.png 300w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/14297A-rf-768x434.png 768w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/14297A-rf.png 1910w\" sizes=\"(max-width: 474px) 100vw, 474px\" \/><\/a><\/p>\n<p>The graph below shows some details of an angle scan, namely the first 2 spectra taken at 8\u00b0 and 10\u00b0 angle of incidence for another coating as well as the 100% and 0% spectra after the angle scan. Measurement time for a single spectrum was 1.5 seconds. Note the high quality of the data:<\/p>\n<p><a href=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/spectral-quality.png\"><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-large wp-image-1663\" src=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/spectral-quality-1024x621.png\" alt=\"\" width=\"474\" height=\"287\" srcset=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/spectral-quality-1024x621.png 1024w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/spectral-quality-300x182.png 300w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/spectral-quality-768x466.png 768w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/spectral-quality.png 1729w\" sizes=\"(max-width: 474px) 100vw, 474px\" \/><\/a><\/p>\n<p>Repeatability is excellent \u2013 the graph below shows spectra (60\u00b0, unpolarized radiation) recorded for 3 samples at 2 different days:<\/p>\n<p><a href=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/reproducability.png\"><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-large wp-image-1664\" src=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/reproducability-1024x633.png\" alt=\"\" width=\"474\" height=\"293\" srcset=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/reproducability-1024x633.png 1024w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/reproducability-300x185.png 300w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/reproducability-768x475.png 768w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/reproducability.png 1623w\" sizes=\"(max-width: 474px) 100vw, 474px\" \/><\/a><\/p>\n<p>Using the polarizor restricts the usable spectral range to 350 \u2026 1050 nm \u2013 below 350 nm the efficiency of the polarizor is poor. However, taking spectra in s- and p-polarization provides very valuable information for reliable thin film analysis.<\/p>\n<p>Here is a scan of a plain glass laminate (i.e. without thin film coatings) in p-polarization, nicely showing the Brewster angle of glass around 55\u00b0:<\/p>\n<p><a href=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/brewster-angle.png\"><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-large wp-image-1665\" src=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/brewster-angle-1024x631.png\" alt=\"\" width=\"474\" height=\"292\" srcset=\"https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/brewster-angle-1024x631.png 1024w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/brewster-angle-300x185.png 300w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/brewster-angle-768x473.png 768w, https:\/\/wtheiss.com\/wordpress\/wp-content\/uploads\/2016\/06\/brewster-angle.png 1721w\" sizes=\"(max-width: 474px) 100vw, 474px\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The WOSP RT-DESKTOP spectrometer system records absolute reflectance and transmittance spectra of glass panes or other flat and shiny samples. Measurements are done in a few seconds. A wide range of angles of incidence is possible: 8\u00b0 to almost 80\u00b0 (depends on sample thickness) for reflectance, and 0\u00b0 to almost 80\u00b0 (depends on sample thickness) [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[207],"tags":[],"_links":{"self":[{"href":"https:\/\/wtheiss.com\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/578"}],"collection":[{"href":"https:\/\/wtheiss.com\/wordpress\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wtheiss.com\/wordpress\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wtheiss.com\/wordpress\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/wtheiss.com\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=578"}],"version-history":[{"count":11,"href":"https:\/\/wtheiss.com\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/578\/revisions"}],"predecessor-version":[{"id":1672,"href":"https:\/\/wtheiss.com\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/578\/revisions\/1672"}],"wp:attachment":[{"href":"https:\/\/wtheiss.com\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=578"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wtheiss.com\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=578"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wtheiss.com\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=578"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}