TABLE OF CONTENTS Chapter 4 introduces you to the types of transducers used to measure temperature, pressure, flow, displacement, velocity, acceleration, force, and load. These are the measurements that are most commonly carried out in test laboratories and production facilities.
Each of the specific measurements can be made with a variety of transducers that have different operating and physical characteristics. Descriptions of the various transducers are provided to help the user select the best transducer for a particular application.
The transducers used to measure temperature include RTDs, thermocouples, thermistors, integrated circuit sensors, and infrared sensors. The operating principle, advantages, and disadvantages are provided for each type of transducer.
In contrast to other physical parameters, there is no common, universally accepted definition of temperature. Definitions for temperature can range from an object's relative sense of warmth or coolness to a measure reflecting the average kinetic energy associated with the motion of the molecules that make up a material. Temperature is an intrinsic property of matter that quantifies the ability of one body to transfer heat energy to another body. Heat flows from a high temperature area or body to a low temperature area or body. If a high-temperature body is put in contact with a low-temperature body, heat energy will decrease in the hot body and increase in the cooler body until a thermal equilibrium is reached. At the molecular level, the velocity of the molecules in the hot body will decrease as they...
