Is there an accepted universal standard for the calibration of color Spectrophotometer? Are there white standards available with certified reflectance values?
The universal standard is the theoretical perfect reflecting diffuser (PRD). A PRD is a perfect reflector (reflects 100% of the incident light) and a perfect Lambertian diffuser. No such material actually exists, but pressed PTFE (sometimes called Halon) is a good approximation. Materials are calibrated by national standardizing laboratories to provide reflectance factor data relative to the PRD for a given illumination and viewing geometry. In the USA the national laboratory is NIST. Other examples are NPL in the UK, and NRCC in Canada.
Related Questions
- We always measure the color difference by using d/8 spectrophotometer with included specular reflectance. But why do we always measure the white with excluded one ?
- Is there an accepted universal standard for the calibration of color Spectrophotometer? Are there white standards available with certified reflectance values?
- Does NIST Standard Reference Materials offer color standards?
