Explain how a thermocouple works. What are thermocouples used for?
you will get lots of help using google.
The wiki article is pretty good on this subject:
http://en.wikipedia.org/wiki/Thermocouple
A thermocouple is a device used to measure temperature based on the principle of the Seebeck effect. It consists of two different types of metal wires, usually joined together at one end called the junction, and connected to a voltage measuring instrument at the other end.
When the junction of the thermocouple is exposed to a temperature difference, it generates a small electric voltage. This voltage is directly proportionate to the temperature difference between the hot and cold ends of the thermocouple. This phenomenon occurs because the two dissimilar metals in the thermocouple produce differing electrical potentials when heated or cooled.
The voltage generated by the thermocouple can be measured using a voltmeter or other suitable instruments. By using the relationship between the voltage generated and the temperature difference, the actual temperature at the hot end of the thermocouple can be determined.
Thermocouples are widely used for temperature measurement because of their simplicity, durability, and wide temperature range capability. Some common applications of thermocouples include:
1. Temperature control systems: They are used in various industrial and domestic heating systems, such as furnaces, boilers, and ovens, to regulate and monitor temperature.
2. Industrial processes: Thermocouples are used in industries like petrochemical, steel, glass, and cement production, to monitor and ensure proper temperature conditions.
3. HVAC systems: They are employed in heating, ventilation, and air conditioning systems to monitor and control the temperature inside rooms and buildings.
4. Scientific research: Thermocouples are extensively used in laboratories and scientific experiments to measure temperature accurately in various setups.
5. Automotive industry: They are often present in engine management systems to measure temperature for diagnostic purposes and to ensure optimal performance.
It's important to note that thermocouples require calibration to ensure accurate temperature measurements. This involves referencing the thermocouple readings to a known temperature source to correct for any deviations or errors in the measurement.