The Didymium glass filter 666-F7A is made from material specially manufactured by Schott AG. The didymium glass filter’s absorbance behavior in the ultraviolet range also makes it suitable for use as an absorbance filter.
Didymium glass filters are suitable for checking wavelength accuracy (F7W) in the UV-Vis range and photometric accuracy in the UV range.
Absorbance behavior in the UV range can be checked at 270 nm, 280 nm, 297 nm, 321 nm, and 342 nm. Filters are routinely set at a thickness that produces a nominal optical density of 0.5 Abs at 342 nm. This results in increasingly higher absorbances the shorter the wavelengths become.
Selected spectrum for a didymium glass filter between 270 nm and 370 nm measured with a slit width of 1 nm.
The Didymium glass filters' absorbance values vary greatly depending on the glass batch used and can only be compared for filters derived from the same glass melting process. Due to this batch-to-batch variation, all Didymium glass filters are certified individually.
|ARTICLE-NO.||666F7A-323 or 666F7-323 Request this article|
|APPLICATION||Checking photometric accuracy |
in UV range (270 nm to 342 nm)
|CONTENT||Didymium glass in metal frame|
|STANDARD CERTIFICATION||Wavelengths: 270, 280, 297, 321, 342 nm |
Photometric accuracy at approx. 0.5 - 1.0 Abs
Slit width: 1 nm; with DAkkS calibration certificate
|POSSIBLE CERTIFICATION||Wavelength: between 270 to 280 nm, 297, 321, 342 nm |
Slit width: all up to 2 nm possible