14-05-2012, 03:09 PM
Sensor Technology AND Its Applications
sensor technoloy & its applications.ppt (Size: 3.46 MB / Downloads: 45)
Introduction
Traditionally the output of the sensor was hardwired to some form of interpretive device (e.g., PLC)
Active element of a sensor is called a transducer
A device which provides a usable output in response to a specified measuring is called SENSOR
Classification of Sensor
Classification based on physical phenomena
Mechanical: strain gage, displacement (LVDT), velocity (laser vibrometer), accelerometer, tilt meter, viscometer, pressure, etc.
Classification based on measuring mechanism
Resistance sensing, capacitance sensing, inductance sensing, piezoelectricity, etc.
Thermal quantities: temperature, heat.
Electromagnetic/optical quantities: voltage, current, frequency phase; visual/images, light; magnetism.
Chemical quantities: moisture, pH value
Wireless Sensor Networks
A wireless sensor network is a collection of nodes organized into a co operative network. Each node consists of processing capability may contain multiple types of memory have an RF transceiver, have a power source (e.g., batteries and solar cells), and accommodate various sensors.
Network Model for WSN
A wireless sensor network consists of hundreds or thousands of low cost nodes which could either have a fixed location or randomly deployed to monitor the environment. The flowing of data ends at special nodes called base stations (sometimes they are also referred to as sinks).