Based on WOSP-SUNBLOCK, the WOSP-NOLAB system can be used in glass factories to measure solar reflectance and transmittance (300 … 2500 nm) of large pieces of glass. Total measurement time is about 5 s.
The CODE software used for data acquisition can predict the technical performance data (color, g-value, solar R and T) of arbitrary final glazing products built with the just produced coated pane. All data (spectra, measured and predicted performance data) can be automatically exported to an external SQL database.
Multiple angle reflectance measurements
Glass for buildings and cars may have different appearance with respect to color when the viewing angle changes. The angular dependence of color values is important for the design of glass coatings, and hence it is important to verify that the wanted color values are obtained after coating deposition.
WOSP-MAC (multiple angle color sensor) is a lab instrument that measures color values at fixed angles of incidence of 30°, 45° and 60°.
Measurements can be performed using a very simple software interface – they take about 10 seconds.
Results for various samples are collected in a workbook which can be exported as Excel document.
ICCG 12 conference, June 13, 2018, 3 PM, Würzburg, Germany:
Wolfgang Theiss will give a presentation called ‘Up and down – shifting the limits of optical spectroscopy in large area coaters’
Our software packages are powerful – but also complex. The large variety of possible applications and numerous program features are certainly demanding. An introductory training with focus on the user interface and basics of optical modeling significantly shortens the time it takes new users to get going.
Since our users are distributed world wide we have done more and more remote online training during the last years. It turned out that in most cases the number of questions during the sessions has been small, i.e. usually there is not much interaction. With this rather one-directional lectures in mind, we have decided to adapt our working style concerning software training.
Starting in January 2018 we will start to publish a series of recorded lectures, available and free of charge for everybody. New users can follow these sessions at their on speed and whenever there is space in their agenda. In addition to the introduction of training videos we will intensify the FAQ section of our website, hoping that we will give answers to most typical questions that may arise.
If users are interested in deeper discussion we offer to reserve some hours of intense explanations -however, this will not be in real time, and it will not be for free. We will write answers to written questions or prepare short videos, with some time delay between questions and answers. This way everybody can work at a reasonable time of the day, and no information is lost. You can simply repeat a complex procedure and watch it as long as necessary.
We hope that this new concept will prove useful and comfortable for all participants.
Current video tutorials
We have copied our tutorial videos to a second platform which is available in China. Click the following link:
WTheiss videos on alternative platform
A halogen light, 16 UV-LEDs and an integrating sphere have been combined with 2 spectrometers to the WOSP Sunblock system. It measures reflectance in the range 300 … 1050 nm, with the option to extend the NIR range up to 2500 nm.
The light sources inject radiation into a sphere (76 mm diameter). The intensity at the sphere wall as well as the intensity reflected by the sample are simultaneously recorded with 2 spectrometers. Signals recorded for a reference mirror and the sample are combined to compute the final reflectance of the sample.
The whole block can be mounted on a traverse or a robot arm – only electrical cables leave the system.
The rack mounted system shown above has been used to record some demonstration spectra discussed below. All spectra have been acquired in less than one second.
Since the final spectrum is based on ratios of spectra the absolute light source intensity cancels – this leads to very stable results. The spectra shown below have been recorded with a delay of more than half an hour:
The next set of spectra show reflectance spectra of float glass with SiN layers of different thickness:
The last demo set shows spectra of solar glass with AR coatings, applied on one side only and on both sides of the glass:
The table of results can now be filtered: You can type in a pane ID or select a bright eye (or both) and check the ‘filter’ option – the table will then show results for the selection only. Unchecking the filter option brings you back to the display of all results.
The format of Optoplex NGQ csv files has been changed and we had to modify our import routine to match the new structure of the files – the new procedure is active starting with object generation 4.68. This may eventually cause trouble if you are still working with the older format. Please tell us if that happens …
An error in the computation of carrier mobility for the extended Drude model has been removed. The new (hopefully correct) values are all smaller than the previously computed values.
Once youhave optimized the design of your coating product with respect to angular variation of color you have to check if it really performs as CODE predicts.
The prototype described in this section will do the job: You can record absolute reflectance and transmittance spectra in high quality for the range 8° to 85° of the angle of incidence. The 85° are possible only for thin samples, with thickness below 5 mm. You do not need a calibration mirror since the 100% reference measurement can be done with light source and detector facing directly opposite to each other.
WOSP-ART consists of a light source and a detector mounted on arms which can be rotated individually. Spectra are recorded for the wavelength range 380 … 1100 nm. Extensions to the UV (down to 280 nm) and the NIR (up to 2500 nm) are possible.
Measurements are performed using our CODE software which can export results to data files or external SQL databases.
Here is a video demonstrating the operation of WOSP-ART.