Reference white
Reference white is an ideal achromatic color without any color cast , which is used as a neutral comparison in color measurement . It is used to set the white level, the metrological 100%, in contrast to the black level, the zero.
As a real comparison measurement, measuring surfaces prepared with barium sulphate are mostly used. An important area of application in light measurement technology is, for example, the integrating sphere or standards for colorimetry . Calibrated titanium dioxide with a rutile structure is also used as a useful substance , although it is no longer ideally white towards the ultraviolet . Also, magnesium has uneven remission , but was formerly used as a low-cost commodity.
In this context, “ideally white” means that there is no change in the degree of remission over the entire wavelength range of the required measurement . From this point of view, Teflon washers are particularly suitable for practical use . These have a high uniformity of remission over a wide spectral range. For the same reason, it can also be used to produce good gray standards .
literature
- J. Winkler: Titanium Dioxide . Vincentz Network, Hannover 2003, ISBN 3-87870-738-X .