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.
We have updated the documentation of the connectivity to external SQL databases. SCOUT and CODE can save configurations, materials and measured spectra as well as fit results. The required table structure is generated automatically.
Below is the link to the relevant section of the SCOUT manual:
A new version of the scanner has been released. We have verified that this one can process reflectance measurements taken at 55° angle of incidence, in addition to the ‘normal’ transmission and reflectance spectra recorded at 8° angle of incidence.
Make sure that your BREIN product contains 4 spectra, and that you enter Optoplex names correctly in the conversion tables ‘BE assignment’ and ‘Spectrum nicknames’: Sometimes the database column ‘Resultname’ is ‘OFR155° SB Reflection’, and sometimes it appears as ‘OFR155° SB Reflection Glass’.
You can now open up to 4 inspection windows in BREIN, showing information about 4 different sets of results.
The prediction feature of BREIN transfers the latest fit results and spectra to an internal CODE instance. This can be used to do various kinds of computations, based on the properties of the pane that was investigated last.
In a similar way the new ‘Inspection’ mechanism re-loads historic fit results (and the spectra that were used to obtain these numbers) to a separate CODE instance. This can be configured to let the operators verify the fit results and try what happens if some parameters were modified.
For details please see the updated documentation (page 55 at the moment).
The computation of the total solar heat gain coefficient (g-value) following the rules of standard ISO 52022-3 (2017) has been implemented. The procedure takes into account the temperature change of panes and gases due to absorption and re-emission of solar radiation. The absorbed solar power and the final temperature of each pane are side-results of the routine and are available in addition to the g-value.