Sensors Story

 Sensor is an object that can detect changes in its surrounding environment and provide this change as an output. Sensors are devices that can convert one form of energy to another (i.e. converts a signal in one form of energy to another), thus sensors are known as transducer. There are two basic types of sensors: analog and digital. The two are quite different in function, in application. An analog sensor produces a continuously varying output value over its range of measurement. Digital sensors, on the other hand, have only two states, often called "on" and "off." Sensor's sensitivity indicates how much the sensor's output changes when the input quantity being measured changes (i.e. ratio between output signal (from sensor) and its measured property. A good sensitive sensor is the one that is sensitive to its measured property, on the other hand, it is not sensitive to any other property, and it doesn’t influence the measured property.

Sensors has another quantity known as the resolution, which is defined as the smallest change in the measuring property the sensor can detect, the resolution is related to the precision with which the measurement is made. Sensors are chosen depending upon criteria, given as follows:
1. Sensor Accuracy
 2. Environment surrounding the sensor
 3. Measurement limit of the sensor
 4. Calibration
 5. Resolution
 6. Repeatability