Standard Reference Materials: Standard Quartz Cuvettes for High-Accuracy Spectrophotometry

Abstract

Abstract Accurate knowledge of lightpath and parallelism of cuvettes used in spectrophotometry are indispensable parameters that must be determined when accurate transmittance measurements of liquid materials are considered. A description is given of the design and techniques developed at NBS for production of quartz cuvettes (SRM 932) having a nominal radiation pathlength of 10 mm ± 0.03 mm. For each cuvette, pathlength and parallelism are certified with an uncertainty of ±0.0005 mm. The method and instrumentation used to determine these parameters are also described.