The proposed new work item, Glass beads for road materials - Determination of refractive index using secondary rainbow method, would provide a procedure for determining the refractive index of glass beads for road materials such as road marking materials and reflective films using the secondary rainbow method. If the work item is approved, the work would be carried out by a project committee.
The refractive index of the glass beads is a key parameter affecting the optical performance of the retro-reflective road materials. According to the proposal, the immersion method is currently the main test method for the refractive index of glass beads for road materials, but has two main drawbacks: a) the high refractive index matching liquid is toxic to the human body, and b) the immersion method cannot always meet the need for accurate values of the refractive index of glass beads required in some occasions. According to SAC, the proposed new work item would provide a safe and more accurate alternative to the immersion method, and would help to facilitate open and fair trade.
All comments on the proposal should be sent to Steven P. Cornish, ANSI senior director for international policy ([email protected]). Feedback received by the April 27 deadline will be reviewed and compiled for the recommended ANSI position and comments, which will then be presented to the ANSI ISO Council (AIC) for formal approval.
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