Temperature Sensor

1.What is a temperature sensor?

• This measure the temperature of the environment. These sensors detects the outer surroundings and then converts the input date into electronic data to record, monitor, or signal temperature changes. The basic principle of working of the sensors is based on the voltage across the diode terminals. If the voltage increases, the temperature also rises, followed by a voltage drop between the transistor terminals of base and emitter in a diode.

2.What are the types of temperature sensors?

• Thermocouples

  • A thermocouple is a electronic device that consists of two dissimilar electrical conductors forming an electrical junction. A thermocouple produces a temperature-dependent voltage as a result of the thermoelectric effect, and this voltage can be interpreted to measure temperature.

• Resistor Temperature Detector (RTD)

  • The resistance temperature detector (RTD), is a thin film device made of platinum, which is used for measuring temperature. It has great stability, accuracy and repeatability. The temperature is directly proportional to the resistance. Higher the resistance means larger the resistance.

• Thermistors

  • A thermistor is a type of resistor whose resistance is dependent on temperature, more so than in standard resistors. They can do more than simply regulate temperature. These sensors are also used for voltage regulation, volume control, time delays, and circuit protection.

• Semiconductor Sensors

  • Semiconductor sensors, or integrated circuit (IC) sensors, operate with reverse bias, have a small capacitance and a low leakage current. 

• IR sensor

  • An infrared (IR) sensor is an electronic device that measures and detects infrared radiation in its surrounding environment. There are two types of infrared sensors: active and passive.

3.Which is the most accurate temperature sensor?

• An RTD is the most accurate and stable sensor and is more linear than a thermocouple or thermistor. However, RTDs are the slowest and most expensive sensors. Therefore, precision applications where accuracy is critical while speed and cost are less important.

4.What are the applications of a temperature sensor?

• These sensors have a wide range of applications where maintaining a specific temperature is vital. The sensor will indicate when the environment becomes too hot or cold and preventative action can be taken to ensure that the entire device is not compromised. Many industries including medical, motorsport, HVAC, agriculture, industrial, aerospace and automotive use the sensors to check the temperature of its surroundings.