The ASTM Colour scale as specified in ASTM D1500 is a standard test method for colour grading of petroleum products. The scale is defined by 16 glass standards of specified luminous transmittance and chromaticity, graduated in steps of 0.5 from 0.5 for the lightest colour to 8.0 for the darkest. It is intended for a variety of petroleum products such as lubricating oils, heating oils, diesel fuel oils, mineral insulating oil and solid petroleum waxes and has been adopted by many other standardising bodies as listed below.
The Lovibond® AF 509/C is a special kit for visual colour grading of type F76 marine diesel fuels according to a limited range of the ASTM Colour Scale. It is designed to ensure that the correct fuel is used in motor vessels running with type F76 diesel, thereby avoiding errors in fuel use that can result in expensive corrective maintenance. The test is based on a direct colour match between the sample and a test disc containing ASTM Color standards, enabling the operator to accept or reject the diesel fuel in a matter of minutes.
The Lovibond® AF 509/C includes a test disc containing a limited range of ASTM Color standards (1 - 5 units as opposed to the full range of 0.5 - 8 units), which is sufficient for this purpose since type F76 fuel has a target colour of 3.5 ASTM Color. The sample (in a 33 mm glass cell) is compared with the colour standards in a Lovibond® Comparator 2000+ until a colour match is obtained.
The Lovibond® AF 509/C is supplied with the following equipment in a plastic carrying case:
ASTM Colour Disc 4/81 - Test disc containing 7 coloured glass standards precalibrated to 1, 2, 3, 4.5, 4, 4.5, 5 ASTM Colour Units
2 x W680/OG/33 cells