General Information:

Pt-Co/Hazen/APHA Colour (ASTM D1209) colour reference standards are manufactured and certified by The Tintometer Limited. These colour standards have been manufactured and tested under the control of Tintometer's ISO 9001 Quality Management System. Often referred to as Pt-Co, Platinum-Cobalt, Hazen or APHA Colour. All terms are interchangeable and equally valid. Typically used to measure clear to dark amber liquids. 
Originally defined by specified dilutions of a platinum-cobalt stock solution, ranging from 0 at the light end of the scale to 500 at the darkest. Used extensively in the water industry but also for clear oils, chemicals and petrochemicals such as glycerine, plasticisers, solvents, carbon tetrachloride and petroleum spirits. Typically used in, but not limited to, ASTM D1209, ASTM D5386, ISO 6271.  

• Typically used in, but not limited to, the analysis ofclear oils, chemicals and petrochemicals such as glycerine, plasticisers, solvents, carbon tetrachloride and petroleum spirits
• Supplied in tamper-evident glass packaging, providing assurance of sample integrity
• Available as a single 500 mL pack
• Manufactured in the United Kingdom
•12-month shelf life

Downloads:
ARO Scientific SDS-0001 Total Acid Number5.pdf