ABSTRACT
This chapter describes various types of sensors for measuring different physical parameters. A sensor is a device that provides an electrical output responding to a stimulation of a nonelectrical signal. It converts a physical parameter into a signal suitable for processing. Sensors are widely used in various places such as automobiles, airplanes, radios, and countless other applications. In a control system, displacement or distance is an important parameter to be measured. Depending on the distance range, various types of sensors are used. The most popular sensors for large distance measurement are optical sensors. Laser triangulation sensors are specially designed optical sensors for more precision position measurements over short and long ranges. Ultrasonic distance sensors measure the traveling of ultrasonic pulse. Many modern pressure sensors are much more sensitive than scales and give an accurate output that can be measured electronically. The capacitive pressure sensors use capacitance sensitive components to transform the pressures to electrical signals.
