Reflectance standards made from ultrapure Optical PTFE by Berghof are used for calibration of optical instruments in the optical measurement technology. The special surface structure of the material results in a diffuse, lambertian reflection of up to >99 %R. When adding specific black pigments, they can also be produced in further gray scales. Due to the high material thickness of the volume reflectors of 10 mm, the highest possible diffuse reflection of a wide wave length (250–2,500 nm) can be reached and therefore makes the reflectance standards a perfect reference measurement area for calibration or the white balance of optical devices. Another advantage: The measurement area can be cleaned through the removal of the top, contaminated material layer.
Advantages
Extremely diffuse reflection of up to >99 %R, evenly across a wide wave length of ~250–2,500 nm
Refractive index ~1,38
Surface homogeneity +/– 0,1 %R
High energy density limit of up to ~8 J/cm² (laser damage threshold)
Different gray scales for calibrated reflection: 70, 50, 20, 5, 2 %R
Surface homogeneity (gray scales) +/– 1 %R
Linearity of spectrum (gray scales) +/– 0,5 %
Temperature resistance of –200 to +260 °C (temporarily +300 °C)
Highest UV stability and universal chemical resistance, no discoloration
Easy, mechanical cleaning
Applications
Calibration of
- Colorimeters
- Radiometers
- Photometers
- Spectrophotometers
- Densitometers
- Integrated spheres systems
- Reflectometers
Linearity testing of
Detector systems
Colorimeters
Densitometers
Spectrophotometers
