Standard reference materials: standard quartz cuvettes for high-accuracy spectrophotometry.

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. Additional Keyphrases: lightpath #{149} instrumental path-