TABLE OF CONTENTS This chapter will help you understand the difference between temperature and heat, the units used for their measurement, thermal time constants, and the most common methods used to measure temperature and heat and their standards.
Topics covered in this chapter are as follows:
The difference between temperature and heat
The various temperature scales
Temperature and heat formulas
The various mechanisms of heat transfer
Specific heat and heat energy
Coefficients of linear and volumetric expansion
The wide variety of temperature measuring devices
Introduction to thermal time constants
Similar to our every day needs of temperature control for comfort, almost all industrial processes need accurately controlled temperatures. Physical parameters and chemical reactions are temperature dependent, and therefore temperature control is of major importance. Temperature is without doubt the most measured variable, and for accurate temperature control its precise measurement is required. This chapter discusses the various temperature scales used, their relation to each other, methods of measuring temperature, and the relationship between temperature and heat.
Temperature is a measure of the thermal energy in a body, which is the relative hotness or coldness of a medium and is normally measured in degrees using one of the following scales; Fahrenheit (F), Celsius or Centigrade (C), Rankine (R), or Kelvin (K).
Absolute zero is the temperature at which all molecular motion ceases or the energy of the molecule is zero.
Fahrenheit scale was the first temperature scale to gain acceptance. It was proposed in...
