Thermocouple Sensors are devices used to measure temperature. They work by measuring the voltage generated by contact between two different metals. When the temperature changes, the voltage will also change.
The working principle of the thermocouple sensor
A thermocouple consists of two metals with different electrical properties. When the two metals are connected at one end and touched to the temperature to be measured, a voltage called **Thermoelectric Voltage** or **Seebeck Effect** will be generated at the other end. This voltage will vary depending on the temperature at which it is touched, which can be converted to a temperature value.
Types of thermocouples
1. Type K thermocouple
- Chromel (nickel-chromium) and Alumel (nickel-aluminum) materials
- Temperature range -200°C to 1,260°C
- Applications Commonly used in industry Because of its stability and wide measurement range
2. Type J thermocouple
- Iron and Constantan (nickel-copper) materials
- Temperature range -40°C to 750°C
- Application Suitable for use in lower temperatures and dry environments
3. Type T thermocouple
- Copper and Constantan materials
- Temperature range -200°C to 350°C
- Application Suitable for measuring low temperatures, such as in laboratories or applications that require accuracy at very low temperatures
4. Type E thermocouple
- Chromel and Constantan materials
- Temperature range -200°C to 900°C
- Application Suitable for measuring low temperatures and high accuracy
5. Type S, R, and B thermocouples (Type S, R, B)
- Platinum and Rhodium materials In different ratios
- Temperature range Up to 1,760 ° C (Type B up to 1,820 ° C)
- Application Used in industries that require very high temperature measurement, such as glass and ceramic production
Advantages of thermocouple sensors
- Wide measurement range Thermocouples can measure temperatures from very low to very high temperatures
- Durability Thermocouples can withstand harsh environments, such as high temperature, high pressure or corrosion
- Fast response Thermocouples can respond quickly to temperature changes
Limitations of thermocouple sensors
- Lower accuracy than some other technologies When compared to other temperature sensors, such as RTD (Resistance Temperature Detector), thermocouples may have lower accuracy
- Effect from noise The voltage generated by the thermocouple is very small, causing noise from the environment to affect the measured value
Common applications of thermocouple sensors
- Industrial temperature control, such as furnaces, heating systems or metal production
- Engine temperature measurement Used to measure the temperature of exhaust gases or internal engine parts
- Research and development Used for testing and developing devices that require accurate temperature measurement over a range.
