Definition: Temperature sensor consisting of two dissimilar metal wires joined at one end. When heated, generates a small voltage proportional to temperature, which can be measured and converted to temperature reading.
Types:
- **Type K**: -200°C to +1,260°C, most common in cold chain
- **Type T**: -200°C to +350°C, good for cryogenic applications
- **Type J**: -40°C to +750°C, industrial applications
Advantages:
- Rugged, durable
- Wide temperature range
- Fast response time
- Inexpensive
Disadvantages:
- Lower accuracy than RTDs (±1-2°C typical)
- Requires reference junction compensation
- Calibration drift over time
Related Terms: RTD, Temperature Sensor, Temperature Monitoring, Data Logger