Book excerpt: Over one in five thermometers currently in use are out of calibration. This self-teaching text seeks to redress this situation by providing practical guidance on temperature measurement and calibration. Focusing upon recognised measurement procedures and international standards, the authors detail the operating and measurement principles for the four most common thermometers: platinum resistance, liquid-in-glass, thermocouples, and radiation thermometers. Features include the latest temperature information including ITS-90 reference tables for thermocouples and platinum resistance thermometers; detailed coverage of traceability; how to make traceable measurements and how to design, carry-out and report calibrations; identification of the main contributing uncertainties for a range of thermometers; extensive advice on accuracy, with sections devoted to the recognition and treatment of errors; technical information to complement the managerial guidelines of the ISO 9000 series QA systems. The systematic approach will assist those seeking accreditation along the lines of ISO Guide 25; and illustrative examples, detailed references and a full bibliography.