TABLE OF CONTENTS Chapter written by F. PEETERS, M. PEETERMANS and Luk INDESTEEGE.
Drawing a good glass of beer, pasteurizing milk or producing electricity are all processes that require accurate temperature measurement. Various methods of performing the measurement, each with its own characteristics and possibilities, are described in this module. In the first part, concepts that are commonly used in thermal measuring techniques are explained. We start with a definition of heat and temperature and then give different methods to measure a temperature. The necessity of thermal equilibrium is demonstrated with an example.
The second part deals with ways to measure temperature: glass thermometer, liquid filled thermometer, liquid filled expansion thermometer, pressure temperature detector, vapor-pressure temperature detector and bimetallic thermometer.
These five possible ways to measure temperature are followed by measuring principles, the construction and application of sensors such as thermocouples, resistance temperature detectors (RTDs) and monolithic temperature sensors. In the final part the practical possibilities of pyrometry are described.
First some concepts and thermal units are explained: heat and temperature, static and dynamic readings, time constant and response time, thermal units, thermal equilibrium, temperature reading options and the quality of a measurement.
Heat is the total amount of kinetic energy of the molecules and atoms in a specific object. The molecules of each substance are constantly moving: in solids they move around a certain equilibrium point, while in liquids and gasses they basically move freely.
Because the molecules keep colliding with each...
