 Hello friends, I hope you all are doing great. In today’s tutorial, we will have a look at What are Temperature Sensors and their implementation in different engineering projects. The most significant parameter in industries and different engineering project is the temperature that determines the working conditions of the surroundings or instruments. The correct value of the temperature is essential for the implementation of the different accessories and components in engineering projects, circuits, in medical labs, different research laboratories. To measure different values of the temperature different types of sensors are used.

Mostly used temperature sensors are thermistors, thermocouples, infrared radiation detector, and RTD. In today’s post, we will have a look at uses, working, construction and different parameters related to temperature sensors. So let’s get started with what are temperature sensors.

#### What are Temperature Sensors

• The numerous kinds of temperature sensors are available in the market according to their use like a thermistor, resistance temperature detectors, etc.
• Every sensor has a different working principle like RTD measure temperature by variation in the resistance and thermocouple measure temperature by variation voltage at its terminals.

#### Units of Temperature

Celsius

• Celsius is mostly used temperature unit in the different engineering and industrial temperate measurements.
• It is an experimental scale that was formed by ancient development,  that defined its 0 points by comparing it to the freezing point of water and its hundred degrees compared with the point at which water boiled.

Fahrenheit

• This unit is used by metrologists for the measurement of the surface temperature. But mostly used temperature unit is Celsius so it can be easily converted into the Celsius by using this formula.

C = (F-32)/1.8

Kelvin

• This unit of temperature is used for the different scientific temperature measurements. It can also convert into the Celsius by this formula.

k=C +273

#### Types of Temperature Sensors

• There are numerous categories of temperature sensors according to their working principle, applications and method of temperature measurement.
• We will discuss different and commonly used kinds of temperature sensors some important sensor are listed below. Let’s discuss all these senors with the detailed.
• Thermometer
• Thermistor
• Resistor temperature detectors (RTDs)
• Semiconductor
• Infrared Sensors

#### Thermocouples

• The thermocouple is the abbreviation of TC, it is generally used the sensor for temperature measurements.
• The physical structure of these sensors is very strong, less expensive, there is no need for separate power supply for this sensor, it has an internal battery.
• This module comprises of the 2 different metals that are recognised as open and closed. The working phenomena of the metals of the thermocouple follow the thermoelectric effect.
•  For the safety of thermocouple from different environments factors like temperature, moisture, pressure, and gases it is covered with plastic and different ceramic materials sheets.
• The general categories of the thermocouple are K, T, E, S, and B. The J, T, K are generally used thermocouples for temperature computations. #### Resistor Temperature Detector

• The temperature’s value calculates by the RTD has higher accuracy than other sensors.
• As with the variation of the resistance it measures the temperature, its resistance variation is directly proportional to the temperature values.
• The materials that are used for the construction of this sensor are Pt (platinum), nickel (ni) and copper (Cu).
• It can measure temperature form the minus two seventy celsius to eight fifty celsius.
• In this module, there is no internal power supply it needs external supply for continuous work.
• But the due current power loss occurs at the resistance that can be calculated by this formula.

ΔT = P x S

#### Thermistors

• A thermistor is a less costly, adjustable and can be used in easiest way. It measures the value of the temperature by the change in the resistance.
• Ther are 2 main types of the thermistors first one is NTC (negative coefficient thermistor) and second is PTC (positive temperature coefficient).
• In the case of the PTC, the temperature and the resistance is directly proportional to one another, with the increase of the temperature there is also an increment in the resistance.
• While in the  NTC the temperature and resistance are inversely proportional to each other.

#### Thermometers

• To measure the temperature of the different matters like fluids, gaseous materials, and solids the thermometer is used.
• The word thermometer is a mixture of the 2 different words first one thermo that means heat and the second one is the meter that means to measure something.
• The thermometer is similar to a tube that is assembled by the glass and consists of the mercury.
• When the temperature rises the mercury in the tube expands according to the temperature and temperature value can be measured from the scaling on the wall of the tube.
• The value of the temperature can be measured in k (kelvin), F (Fahrenheit), centigrade (C) according to the set scale. 