TABLE OF CONTENTS The most common electronic temperature measurement devices currently available include the thermocouple, the resistance temperature detector, the thermistor, and the integrated circuit temperature transducer. All have associated application benefits and limitations which are delineated in Table 14.2 [3].
| Characteristic | Platinum RTD | Thermistor | Thermocouple | Silicon | |
|---|---|---|---|---|---|
| Thin-film type | Wire wound type | ||||
| Active material | Platinum thin film | Platinum, wire wound | Metal oxide ceramic | Two dissimilar metals | Silicon transistor cascade |
| Relative sensor cost | Moderate to low | Moderate | Low to moderate | Low | Low |
| Relative system cost | Moderate | Moderate | Low to moderate | High | Low |
| Temperature range | ?200 C to 750 C (560 C max. typ.) | ?200 C to 850 C (600 C max. typ.) | ?100 C to 500 C (125 C max. typ.) | ?270 C to 1800 C | ?40 C to 125 C |
| Changing parameter | Resistance | Resistance | Resistance | Voltage | Voltage |
| Base value | 100 ? to 200 ? | 100 ? | 1 k ? to 1 M ? | <10 ? V at 25 C | 750 mV at 25 C |
| Interchangeability | 1%, 3 C | 0.06%, 0.2 C | 10%, 2 C typ. | 0.5%, 2 C | 1%, 3 C |
| Stability | Excellent | Excellent | Moderate | Poor | Moderate |
| Sensitivity | 0.39% K ?1 | 0.39% K ?1 | ?4% K ?1 | 40 ? V K ?1 | 10 m V K ?1 |
| Relative sensitivity | Moderate | Moderate | Highest | Low | Moderate |
| Linearity | Excellent | Excellent | Logarithmic, poor | Moderate | Moderate |
| Slope | Positive | Positive | Negative | Positive | Positive |
| Noise susceptibility | Low | Low | Low | High | Low |
| Lead resistance errors | Low | Low | Low | High |
