Book Description

The monograph describes the methods and equipment employed at the National Bureau of Standards for calibrating standard platinum resistance thermometers (SPRT) on the International Practical Temperature Scale (IPTS-68).The official text of the scale is clarified and characteristics of the scale are described.Several designs of SPRT's are shown and discussed in the light of the requirements and recommendations on the text of the IPTS-68.Possible sources of error such as those due to the internal and external self-heating effects and the immersion characteristics of SPRT's are described in detail.Precautions and limitations for the mechanical and thermal treatment and for the shipment of SPRT's are indicated, and a guide is given for those desiring the thermometer calibration services of NBS.(Modified author abstract).