SENSOR: The sensor is a transducer type, it is used to sense or detect events or changes in physical quantities and gives a corresponding analog output. TYPES OF SENSOR: 1. IR sensor. 2. proximity sensor. 3. Temperature sensor. 4. Pressure sensor. 5. Light sensor. 6. Fires sensor.
RTD Means RESISTANCE TEMPERATURE DETECTOR. Working:- The resistance of certain metals changes with temperature change. RTD Materials:- 1. PLATINUM 2. NICKEL 3. COPPER are generally used. Temperature Range: –200 to 650o c. RTD with wheatstone bridge circuit The changes in resistance caused by the changes in temperature are detected by the wheatstone
A thermocouple consists of two dissimilar material wire joined together at one forming a hot junction. The two wires are terminated at other end. This junction called reference or cold junction. The cold junction is maintained at a known constant temperature called reference temperature of thermocouple. The scientist see back discovered that when a
The name Thermistor is derived from Thermally Sensitive Resistors. These are two types namely NTC and PTC. Thermistors have negative temperature coefficient of Resistance. Working:– When temperature increases, the resistance of Thermistor decreases and vice versa. Thermistors sre semiconductors made from a specific mixture of pure oxides such as:- NICKEL