Standard reference materials 933 and 934: the National Bureau of Standards' precision thermometers for the clinical laboratory.

Because many facets of clinical laboratory work, such as enzymatic reactions, pH measurements, and blood-gas analysis, are highly sensitive to temperature, there is a need to measure temperature accurately and closely control it. To help satisfy these needs and to aid in getting a usable temperature scale into the clinical laboratory, the National Bureau of Standards has developed SRM 933 and SRM 934. These precision thermometers are calibrated at 0, 25, 30, and 37 °C. Their value to the clinical laboratory is described.