The Spectral Photometer

A more precise procedure of colorimetry

In order to measure colours very accurately, it's better to use a spectral photometer instead of a densitometer. It is much more precise.

The spectral photometer illuminates a colour sample from all sides in 45° angles (to avoid reflection). The light that is remitted from the sample is deflected (using a tilted mirror) to a prism or diffraction grating.

The colour prism splits the polychromatic light into it's colour spectrum, which is in turn registered and analyzed by about 35 photo cells.

Spectral photometers can be used for colour comparison, for example to compare a print product with the colour sample. It is also used in quality checks for printing units.

The colours are automatically measured in the printing unit, and if deviations occur, they are instantly corrected. This process guarantees consistent, correct colours.