Process colour measurements of liquids are a vital part of many operations where precise process control and high product quality standards are desired.

Color measurements are commonly used for number of reasons, including:

   * color addition control

   * color removal control - optimize filtration or ion beds used to strip color

   * color avoidance - leak detection, yellowness caused from overheating or charring, contamination detection

   * dilution and dosing control

   * quality assurance & control

Some common color scales used in the chemistry industry include:

Hazen (APHA) is a measure of yellowness originally designed to evaluate the color of near-colorless waste waters by visual comparison with a platinum-cobalt (PtCo) stock solution.

Iodine color ranges from yellow to brown defined by specified dilutions of an iodine solution.  Used for solvents, plastics, resins, oils and fatty acids.  

Saybolt (ASTM) covers the determination of the color of refined oils such as undyed motor and aviation gasoline, jet propulsion fuels, naphthas and kerosene, and, in addition, petroleum waxes and pharmaceutical white oils.

A Kemtrak DCP007 in-line photometer can instantly detect minute changes in color that is beyond the sensitivity of the human eye and will furthermore eliminate operator interpretation errors.

The Kemtrak DCP007 photometer uses an absorbing wavelength to measure minute color changes in the process medium, while a second reference wavelength that is not absorbed by the process medium compensates for turbidity and/or fouling of the optical windows. The resulting measurements are very accurate with low drift and long-term calibration stability.

Colour measurement