Saybolt (ASTM D 156) Color Scale


  • +30 to -16 Saybolt color scale (ASTM D 156)
  • Color of refined petroleum products
  • Real time continuous measurement
  • Zero maintenance
  • High temperature & pressure operation
  • Suitable for use in zone 1 hazardous areas (EExD)

The ASTM D 156 Saybolt color scale is used in the petrochemical and pharmaceutical industries to grade the yellowness of pale liquid products and to monitor product contamination. The Saybolt color scale is applicable to a wide range of petroleum products, such as undyed motor and aviation gasoline, jet propulsion fuels, naphthas and kerosene, in addition to petroleum waxes and pharmaceutical white oils.

The Saybolt color scale traditionally relies upon matching a standard colored disc viewed through an adjustable volume of sample. This one dimensional color scale is prone to operator bias and error due to slight variations in the way different operators will perceive color. In essence, color is simply how our brains respond to different wavelengths of light and such a process can be standardized and automated using a Kemtrak DCP007 LED process photometer.

Saybolt ASTM D 156 color Application Note
NGL color monitoring
DCP007 Product Brochure

The Kemtrak DCP007 utilizes a long life LED light source, precision optical filters and robust industrial grade fiber optics to provide a Saybolt color analyzer with outstanding performance and reliability. A proprietary dual wavelength four channel measurement technology ensures precise trace color measurement. A primary “absorbing” wavelength approximates the perception of the human eye, while a secondary reference NIR wavelength not influenced by the sample color is used to compensate for turbidity and/or fouling of the optical windows.

Since optic fibers are used to pipe light to the measurement point and back, the measurement cell contains no electronics, moving parts or sources of heat and is well suited for hazardous and extreme environments.

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