6.2 Colouring
Each technical data sheet lists the internal transmittance
(
)from 280 nm to 2400 nm. To express absorption, a
column headed "Colouring" is provided in the data sheet. Colouring can be determined by measuring spectral
transmission (10 mm sample thickness) including reflection losses. The wavelengths corresponding to 80%
transmission and 5% transmission are given. For example, a glass with the following transmission:
| 80% at wavelength of 404 nm 5% at wavelength of 355 nm |
is indicated in the catalogue as 40/36.
Please note, for the glass types S-TIH53 and S-LAH58, reflection losses are so large that the wavelength corresponding to 70% has been used in place of 80%.
6.3 Specific Gravity (d)
Specific gravity is the density value of well-annealed glass referenced against pure water at 4°C. Each specific gravity value is given to the second decimal place.