Today we receive our first spectrometer. Since we are going to produce glass coatings for architectural applications, we have to be able to record reflectance and transmittance spectra from the UV to the infrared, i.e. at least from 300 to 2500 nm. We bought a machine that covers the range 200 ... 2500 nm.
In order to analyze the measured spectra and to predict optical properties of our thin film products we bought the CODE software from M.Theiss Hard- and Software. The program is installed today.
Our first substrate arrives: FLOAT A is a float glass that we can buy from a supplier in thicknesses of 4, 5, 6, 8 and 10 mm. The test sample we receive has a nominal thickness of 5 mm. We instantly record a reflectance and a transmittance spectrum with our new spectrometer S1. The measured spectra will be of interest for some people in the company, so it would be good to make them public somehow. The best way to do this is to implement a shared database.
Starting the VirCoC database
In order to synchronize our work we decided to build up the VirCoC database. It will be used to store data and documents of common interest. The database is simply realized as a folder structure available to all interested users in our company network. Since the CODE software comes with a database using a certain folder structure we just follow and extend the CODE system.
The CODE setup routine installs a database in the program folder. The database folder is called 'database' and it has the subfolders 'materials', 'substrates' and 'coatings'. 'Materials' contains a lot of optical constant objects, most of them fixed data tables from literature, but also a few optical constant models. The folders 'substrates' and 'coatings' offer some pre-defined layer stacks that you can use as blocks to build up your own stack definition.
Besides the folder 'database' the CODE setup installs a folder system called 'My database'. This is almost empty and is meant to be used as a template for your own database. In order to start with the VirCoC database we copied the 'My database' folders to the network path that is going to hold the database of our company.
At this moment, our database has the folders 'materials', 'substrates' and 'coatings'.
In order to collect important measured spectra we manually add the subfolder 'spectra'. Since at the moment we want to publish the measured reflectance and transmittance of the FLOAT A substrate in the database, a subfolder 'float glass' and therein the subfolder 'Float A' is created. Within this folder the reflectance spectrum is stored in the file r_5mm_s1.spc. The corresponding transmittance spectrum is saved in the file t_5mm_s1.spc. See graphs of these spectra in the Float A database section.
Computation of the substrate absorption
Having measured the reflectance R and the transmittance T of the 5 mm sample of Float A, it is useful to compute the absorption 1-R-T. The small program 'Data Factory' (delivered with CODE) is the right tool to do this. In Data Factory you can load spectra in data fields, and then use the spectral values as numbers in user-defined functions in order to compute new spectra.
First the measured transmittance spectrum is loaded into the data field C1 using the Import command. With proper graphics settings the spectrum looks like this:
| By the way: Once we have typed in suitable graphics parameters to display a certain type of spectrum we store them in the database for future use. In order to do so, a new folder named 'plot parameters' has been created.
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The reflectance spectrum is loaded into data field C2:
Now, in the main window of Data Factory, we compute the absorption by typing in the formula '100-C1-C2' and selecting a Range from 200 to 2500 nm with 200 data points. The button Apply formula does the calculation leading to the following result:
The computed absorption spectrum is then stored to the database folder 'spectra/Float glass/Float A' using the filename a_5mm_s1.spc.
Since we think we will do absorption computations more often, we store the Data Factory configuration to the database. A new folder 'Software configurations' with the subfolder 'Data Factory' is created. Here we store the complete Data Factory configuration (use the File|SaveAs command) in the file s1_absorption.dtf.