Definition: High-accuracy temperature sensor using metal resistance wire (typically platinum) whose electrical resistance changes predictably with temperature.
Types:
- **PT100**: Most common, 100 ohms at 0°C
- **PT1000**: Higher resistance, less wire-resistance error
- **Thermistor**: Similar principle but non-linear, less expensive
Advantages:
- High accuracy (±0.1°C to ±0.5°C)
- Long-term stability (minimal calibration drift)
- Linear response
- Wide temperature range
Disadvantages:
- More expensive than thermocouples
- Slower response time
- More fragile (thin wire)
Applications:
- Pharmaceutical temperature monitoring (GDP requirements)
- Precision cold room monitoring
- Calibration reference sensors
- Critical process monitoring
Related Terms: Thermocouple, Temperature Sensor, Calibration, SANAS Accreditation