Blogs
What is Y Transmission?
Posted on by Ken Phillips
In addition to representing green in the CIE X, Y, Z tristimulus color scale, the CIE Y is also the 1924 CIE Luminosity or Brightness function which quantifies the way people perceive the relative brightness of equal energy spectral hues. Humans perceive green colors as brighter or more luminous than blue or red. Ken PhillipsMr. […]
What is Hunter Whiteness Index?
Posted on by Ken Phillips
Hunter Whiteness Index [WIH] There are at least half a dozen whiteness indices in use today, and a similar number of legacy whiteness indices no longer in use. There are subtleties among them and it is important to know the forms of these whiteness metrics and conditions for which they are derived for. In general, […]
Do you have a source for EP Opalescence Standards?
Posted on by Ken Phillips
The reference document that defines the visual EP Opalescence scale is: EP 2.2 Physical and Physico-Chemical Methods for color and opalescence EP – European Pharmacopoeia, Section 2.2 Physical and Physico-Chemical Methods, Unit European Pharmacopeia, Strasbourg, France (1997: 15-16) www.pheur.org This method describes the visual evaluation of scattering or opalescence in near clear liquids, typically pharmaceutical, […]
Do you know what Molten Color is?
Posted on by Ken Phillips
FAQ:”A client is asking me to measure something they call “Molten Color’. Do you have any information on this? Do Hunterlab instrument have a function for this color?” 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 […]
Do you have references for the equivalency of CIE inverse instrument geometries?
Posted on by Ken Phillips
FAQ: “…. the schema of the principle of measuring shows other way of light (source of light -> sample -> sphere -> detector) than our Vista (source of light -> sphere -> sample -> detector). Please can you explain me difference between both construction? difference between both results of measuring?” Ken PhillipsMr. Philips has spent the last 30 years in […]
Do you have a source for Magnesium Carbonate powder as top-of-scale?
Posted on by Ken Phillips
For measuring the brightness of some materials, some dated industrial methods cite a Magnesium Carbonate block standard to be set to Y = 100% in reflectance. This is a very old top-of-scale standard and HunterLab does not recommend using it. Ken PhillipsMr. Philips has spent the last 30 years in product development and management, technical […]
What are the USDA Peanut Butter Color Standards?
Posted on by Ken Phillips
The USDA quality system assigns peanut butter quality rating of USDA Grade A, Grade B and Other based on 4 attributes that total 100 points. 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 […]
Do you have a source for calibrated, traceable transmission filters?
Posted on by Ken Phillips
HunterLab does not supply glass or plastic filter transmission standards but here are some sources. 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 […]
Sources for BRDF and BSDF Equipment and Testing Services
Posted on by Ken Phillips
In industrial colorimetry of QA non-luminous materials, assumptions are made that light reflected from or transmitted through a surface is relatively uniform, with only diffuse and specular components. To promote inter-instrument agreement, the CIE geometries for collecting the reflected or transmitted signal of non-luminous materials are standardized into directional and diffuse sphere types. BRDF measurement serves as more of a […]
How is polarization minimized in HunterLab sphere instruments?
Posted on by Ken Phillips
FAQ: “Do you sell a depolarizer for my HunterLab sphere instrument? On occasion we test polarized samples and there is definitely a dependence on the orientation of the lens. I was wondering if adding a depolarizer would eliminate this phenomenon?” Ken PhillipsMr. Philips has spent the last 30 years in product development and management, technical […]
Directional Instruments
Posted on by Ken Phillips
HunterLab manufactures bench top instruments with two different geometry types: directional 45/0 (or 0/45) and diffuse sphere instruments, as discussed in a previous blog note. A 45/0 directional instrument illuminates the sample at a 45˚ angle from the sample surface and the detector is located 0˚ in line perpendicular to the sample surface. The […]