This book provides comprehensive references to practical temperature measurement technologies. It covers: the 1990 international temperature scale; the working principle, characteristics, selection and application of various thermometers; calibration of sensors and temperature measurement systems and standard traceability; special and practical measurement technologies and their applications to characterization of solid surfaces, high-temperature gases, melts, nuclear power generation, waste incineration, anti-corrosion, wear-resistance, flame/explosion prevention, as well as typical fault analysis and countermeasures for on-site temperature measurement practice. The book is closely related to practice, reflecting the relevant new theories, new developments and new trends of thermometry at home and abroad. It condenses the main author's more than 50 years of teaching, scientific research and practical experience in on-site temperature measurement. It can be used as a reference for engineering and technical personnel and workers engaged in thermal measurement and testing in metallurgy, petrochemical, machinery, electric power, and other industries, as well as for teachers, students, and researchers in related majors. The basis of English translation of this book, originally in Chinese, was facilitated by artificial intelligence. The content was later revised by the author for accuracy.