Copyright Goodheart-Willcox Co., Inc. May not be reproduced or posted to a publicly accessible website. Chapter 5 Measurement 77 5.5 Temperature Measurement Temperature is the measurement of the intensity of the heat energy in a material. There are four common temperature scales: Rankine, Fahrenheit, Celsius, and Kelvin. Temperature is measured in degrees, which is signifi by the fied ° symbol beside a number. Temperature Scales (degrees) Rankine Fahrenheit Celsius Kelvin 672 212 Water Boils 100 373 528 68 Standard Conditions 20 293 492 32 Water Freezes 0 273 0 –460 Absolute Zero –273 0 Goodheart-Willcox Publisher 5.5.1 US Customary The most common temperature scale in use in the United States is the Fahrenheit scale, where water at sea level and standard atmospheric pressure freezes at 32°F and boils at 212°F. The Rankine scale (Fahrenheit absolute) uses absolute zero as the baseline, and each degree has the same value as a Fahrenheit degree. The Rankine scale is used for working at ultra-low temperatures. 5.5.2 SI In the SI system, Celsius (formerly called Centigrade) is used. The Celsius scale uses 0°C as the freezing point of water and 100°C as the boiling point. The Kelvin scale (Celsius absolute) uses absolute zero as the baseline, and each degree has the same value as a Celsius degree. Various instruments are used by technicians to measure temperature, including both analog and digital devices. 5