

Blogs
References for Hazen Color Scale
The original references were written by Allen Hazen, a chemist who first defined APHA/Pt-Co/Hazen color scale for the evaluation of water quality on behalf of the American Public Health Association: Hazen, A. A new color standard for natural waters, American Chemist Journal (14:300), 1892. Hazen, A. The measurement of the colors of natural waters, American […]
How do I measure “clear and colorless” Surfactants?
FAQ: “We are in touch with a pharmaceutical company which is looking for a spectrophotometer to measure the color and appearance of cationic surfactants. Can you provide any information on this topic?” Surfactants reduce the surface tension of a liquid as in the use of a dish detergent; the interfacial tensions between two liquids such as in the case of […]
What is the correct light level in lux for a light booth?
FAQ: “I want to measure the lux level for a light box we are using to evaluate the color of garments. I would like to know, how many light boxes are required for a room. One light box has four D65 tube rods. My question, Is there any standard value of lux which we need […]
How does EasyMatch QC-ER software comply with FDA 21 CFR Part 11?
There are several parts to the 21 CFR Part 11 documents with a good overview of 21 CFR Part 11 at the US FDA website. Part C is the key section concerned with electronic records retention. Ken PhillipsMr. Philips has spent the last 30 years in product development and management, technical sales, marketing, and business development in several […]
Where can Liquid Gardner Color Standards be ordered?
Ken PhillipsMr. Philips has spent the last 30 years in product development and management, technical sales, marketing, and business development in several industries. Today, he is the global market development manager for HunterLab, focused on understanding customer needs, providing appropriate solutions and education, and helping to solve customer color challenges across these industries and cultures.
APHA = Pt-Co = Hazen = PCU = Platinum Cobalt Color
“APHA” stands for American Public Health Association Color Scale, the organization responsible for the original definition and implementation of this visual color scale as a standard method for rating water quality. Ken PhillipsMr. Philips has spent the last 30 years in product development and management, technical sales, marketing, and business development in several industries. Today, […]
APHA/Pt-Co/Hazen vs Gardner color scales: What’s the difference?
The APHA/Pt-Co/Hazen and Gardner visual color scales were both originally based on liquid chloroplatinate color standards but have different history and intended use. Ken PhillipsMr. Philips has spent the last 30 years in product development and management, technical sales, marketing, and business development in several industries. Today, he is the global market development manager for […]
Where does one find the EP (European Pharmacopoeia) Liquid Color Matching Standards?
EP – European Pharmacopoeia Color is a visual liquid color scale used primarily in the pharmaceutical industry. It consists of 3 primary color standard solutions (yellow, red and blue) mixed with hydrochloric acid to make 5 standard color solutions – B (brown), BY (brownish-yellow), Y (yellow), GY (greenish-yellow) and R (red). Ken PhillipsMr. Philips has […]
Do HunterLab sphere instruments conform to ASTM D1003?
Yes, but note there are two different approved instrument geometries cited in the ASTM 1003 method. Ken PhillipsMr. Philips has spent the last 30 years in product development and management, technical sales, marketing, and business development in several industries. Today, he is the global market development manager for HunterLab, focused on understanding customer needs, providing […]
Is there an Internet Site for converting and displaying color values?
FAQ: “… Was wondering – do you know of a web site or application where if CIELAB values were entered, the corresponding color would be displayed? Can I also convert from one color scale to another?” Ken PhillipsMr. Philips has spent the last 30 years in product development and management, technical sales, marketing, and business […]
Optimal inter-instrument agreement and communication of color values
To communicate color values effectively, completely specify the 6 parameters of your measurement method and verify that your color measurement is repeatable. These are the key factors to ensure inter-instrument agreement. The best inter-instrument agreement in color measurement at multiple locations occurs when a product is measured with the same instrument model from the same […]