Standard Reference Materials: Metal-On-Quartz Filters as a Standard Reference Material for Spectrophotometry - SRM 2031

摘要

This publication describes in detail the selection, production, testing, and certification of the semi-transparent evaporated metal-on-fused silica filters as a Standard Reference Material for spectrophotometry. Particular attention is given to various factors that can affect the accuracy of the transmittance values established for these filters, such as: reflections, polarization, angle of incidence, and stability in time. Adequate procedures were devised and are described for the protection of the exposed metal layer surface using optical contact, and for the protection of the filter aggregate, by the use of metal holders provided with shutters and of metal storage containers. The data from several interlaboratory tests are also discussed, together with the results obtained on transmittance measurements on 19 sets of chromium-on-fused silica filters, protected by optical contact, which were studied over a period of two years. An Appendix contains the reproduction of several publications relevant to the subject discussed in this work.