FAQ: “Do you know of an independent test lab that can measure Transmittance Haze and Luminous Transmittance?”
HunterLab has several models that measure transmitted haze and luminous transmittance but if you need an independent test lab, contact the following and ask for “TransmittanceHaze testing per ASTM D1003".
Intertek Plastics Technology Laboratories, Inc.
Pittsfield, MA 01201 USA
Tip: To instrumentally measure transmittance haze scattering in accordance with ASTM D1003, If the sample is a transparent solid such as a filter, the instrument is set up on Air as representing a perfect clear medium.
If the sample is a transparent liquid, a transmittance cell of some defined path length filled with distilled water is used as an instrument standard representing a perfect clear material. This procedure is called “standardizing on a blank”.
As a PQ Performance Qualification step, it is a good idea to ask your test lab to read back the Air or transmittance cell + distilled water as a sample. It should always read Haze% = 0; Y Total Luminous Transmittance = 100 closely. Your product results reported in %Haze and Luminous Transmittance will always be measured relative to Air or the cell filled with distilled water.
FAQ: "We are looking for a laboratory who can measure haze on a glass lens (transparent no texture or color) of 0.14%. I have a drawing that also requires 100% dimensions (distances, radius, diameters, etc.)."
For a transparent glass solid, the instrument will be standardized on Air as a perfect clear standard. If you read back Air as a sample, it should read Haze% = 0, Luminous Transmittance = 100. Acceptability on your product at Haze% = < 0.14 is very close to Air. This indices a non-scattering material that is so low that the scattering is not visually apparent. This can only be verified instrumentally.
If the test lab instrument conforms to ASTM D1003 Part B as do HunterLab sphere instruments, it will also be able to read color. If Air is read back as a PQ step representing a "perfectly clear and colorless sample", it should measured L* = 100, a* = 0, b* = 0 D65/10 (indicating no color), Haze% = 0 (indicating no scattering), Luminous Transmittance = 100 (indicating perfect transmittance) relative to Air as a reference.
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