A commonly used color scale to evaluate the pollution levels in waste water is the Platinum-Cobalt scale (Pt/Co scale or Apha-Hazen scale).

This test method is specific to the colour yellow and is based on dillutions of a standard platinum cobalt solutions as defined by ASTM designation D1209, "Standard test method for color of clear liquids (Platinum-Cobalt Scale) and International Standard ISO 6271-1:2004(E), "Clear liquids - Estimation of color by the platinum cobalt scale".

The Kemtrak DCP007 is an accurate maintenance free industrial photometric analyzer that can accurately monitor water color from highly polluted water (>500 Pt/Co units) down to virtually clear water at 1 Pt/Co units.

The Kemtrak DCP007 uses a reference wavelength to compensate for turbidity and/or fouling of the optical windows providing accurate measurements with low drift and long term calibration stabilit