Thermocouples are the simple, robust and inexpensive temperature sensors widely used in various processes and wide temperature ranges. It consists of two different metals, joined at their ends forming a closed circuit and which generates an electromotive force when the two junctions (T1 and T2) are kept at different temperatures.
Thermocouple Operation Diagram:
Thermocouples are available in various types or calibrations, so it is important to carefully select a thermocouple suitable for the specific application.
| Type | Positive Element | Negative Element | Usual Temperature Range | Standard Error Line (Choose Largest) | Special Error Line (Choose Largest) |
|---|---|---|---|---|---|
| T | Copper | Constantan | -200°C~0°C | +/-1°C ou +/-1,5% | –/– |
| T | Copper | Constantan | 0°C~370°C | +/-1°C ou +/-0,75% | +/-0,5°C ou +/-0,4% |
| J | Iron | Constantan | 0°C~760°C | +/-2,2°C ou +/-0,75% | +/-1,1°C ou +/-0,4% |
| E | Chromel | Constantan | 0°C~870°C | +/-1,7°C ou +/- 0,5% | +/-1,0°C ou +/-0,4% |
| K | Chromel | Alumel | 0°C~1260°C | +/-2,2°C ou +/- 0,75% | +/-1,1°C ou +/-0,4% |
| N | Nicrosil | Nisil | 0°C~1260°C | +/-2,2°C ou +/- 0,75% | +/-1,1°C ou +/-0,4% |
| S | 90% Platinum / 10% Rhodium | Pt 100% | 0°C~1480°C | +-1,5°C ou +/- 0,25% | +/-0,6°C ou +/-0,1% |
| R | 87% Platinum / 13% Rhodium | Pt 100% | 0°C~1480°C | +/- 1,5°C ou +/- 0,25% | +/-0,6°C ou +/-0,1% |
| B | 70% Platinum / 30% Rhodium | 94% Platina / 06% Rhódio | 870°C~1700°C | +/- 0,5% | +/-0,25% |
