The main characteristics of thermocouples are:
1. Simple principle - Thermal EMF is generated between two dissimilar metal junctions and directly converted into electric signal.
2. Fast response - Capable of detecting rapidly changing temperatures, with response time typically within 0.1 second.
3. Wide temperature range - Different thermocouple types can measure high and low temperatures from -200°C up to 2500°C.
4. Small size - Thermocouple probes have diameter around 0.25mm only, suitable for small spaces.
5. Easy to use - Simple installation and connection, no external power required.
6. High noise immunity - Not affected by noise, static electricity or electromagnetic fields.
7. Stable and reliable - Long lifespan, can operate continuously in inert gas.
8. Low cost - Thermocouples have low production cost.
9. High accuracy - Premium grade thermocouples up to ±0.1°C accuracy.
10. High reliability - Low failure rates, long service life.
In summary, thermocouples feature simple principle, fast response, flexible usage and are ideal for industrial temperature measurement.