Sensors - Application and Multidisciplinary Aspects of Wireless Sensor Networks - page 11

Chapter 2
Sensors

Goran Rakočević

2.1 Introduction

A sensor is an electronic device used to detect or measure a physical quantity and
convert it into an electronic signal. In other words, sensors are devices that translate
aspects of physical reality into representations understandable and processable by
computers.
In a wireless sensor network, sensors play an important part, as sensing is one
of its central roles. Technology behind sensors, however, is not of major interest
when considering sensor networks, with the emphasis being more on communica-
tion, network management, and data manipulation. Most sensors used in WSN
systems have been developed independently of WSN technology, and these two
fields continue to develop somewhat independently. Nevertheless, any in-depth
discussion of wireless sensor networks, especially when aimed toward providing
the reader with a holistic picture of current capabilities and limitations of wireless
sensor networks, must include sensors.
In this chapter, first we will look at some important issues regarding sensors and
introduce some of the terminology used later in the chapter. Then we move on
to examine basic types of sensors, categorized by the function they perform.
Characteristics of currently available sensors are given, along with a brief overview
of their operating principals. The goal is not to go into a detailed analysis of sensor
technology, but to give the reader a basic notion of how a certain sensor operates,
under which conditions, and with which limitations. This insight should prove
handy when designing a new WSN application. For a more detailed study of sen-
sors and sensing technologies, readers are referred to [ 1 ].
Finally, as this topic puts much emphasis on utilization of WSN technology in
personal and public health, we examine some of the more complex sensing devices
used within this field.