Research Report RR:F07-1009
Research Report F07-1009 presents the results of an internal laboratory study designed to produce reflectivity measurement data suitable for supporting an interim Precision and Bias section for ASTM Standard Test Method F1252. A total of three transparent samples were measured repeatedly by one laboratory to make an estimate of the repeatability and reproducibility that might be expected from a multi-laboratory, Interlaboratory Study. The reflectivity of one sample was measured from each side since it was coated with a partially reflective coating on one side. Also, each sample/side was measured using two different incidence/reflectance angles (20 and 30 degrees). The samples ranged in nominal reflectivity of approximately 0.08 (8 percent) to 0.34 (34 percent). Three separate reflectivity measurements were made of each sample/side/angle using the procedure presented in F1252-08. After all samples were measured, the measurement set-up was disassembled and then reassembled for a repeat measurement (this was intended to partially simulate the effect that one might expect if a different laboratory made the next measurement set). Once the equipment was reassembled, another trio of measurements was made on each sample/side/angle. A total of eight measurement sets were made on each sample over several days. The data were analyzed using ASTM E691 as a guide and values for repeatability and reproducibility for each sample/side/angle were calculated.
F1252-10 Standard Test Method for Measuring Optical Reflectivity of Transparent Materials
Committee F07 on Aerospace and Aircraft
Subcommittee F07.08 on Transparent Enclosures and Materials