RTD Sensors versus TC Series
| Characteristic | Thermocouple (T/C) | Resistance Temperature Detector (RTD) |
| Measurement Range | Wide, -250°C to +2600°C | Narrower, -200°C to +850°C, often limited to a lower temperature by its insulation. |
| Output Signal | Voltage wrt difference in end-to-end temperature |
Resistance change wrt actual temperature |
| Accuracy | Less accurate, 2-4°C typical | More accurate, up to 1°C typical |
| Long Term Stability | Fair, limited to shorter periods | Good, stable over long periods |
| Stability/Drift | Good, but more subject to drift | Excellent, better long-term stability |
| Sensitivity | Lower | Higher sensitivity |
| Interchangeability | Good | Excellent |
| Linearity | Fair linearity, special linearization generally required. |
Better linearity, special linearization still required, but to a lesser degree |
| Self-Heating Error | No self-heating error | Some self-heating error, but low |
| Extension Cable | High effect, must match T/C type and is more expensive |
Lower effect, can use different material, but ultimately limited by lead wire resistance |
| Response Time | Fast (≤ 0.1 seconds typical), but CJC has thermal lag |
Slower (1 to 7 seconds typical) |
| Repeatability | Reasonable | Better & greater standardization |
| Hysteresis | Excellent | Good |
| Signal Strength | Low, prone to EMI | Higher, more EMI resistant |
| Vibration/Shock Resistance | Good resistance | Less resistant than T/C |
| Robustness/Ruggedness | Very good | Good |
| Sensor Dimensions | Very small to very large | Small to medium |
| Measurement Area | Small, single point-of-contact | Larger, whole element must contact, 1” typical |
| Fine Wire Diameter | Small down to 0.25mm diameter | Larger up to 3mm diameter |
| Reference Junction | Required and a significant source of measurement error. Usually requires a stable ambient at cold junction. |
Not required and not a source of error |
| Excitation Required | Not required, self-powered | Yes, reference voltage or current source |
| Lead-Wire Resistance | High, but often mitigated by mating technology |
Must be considered wrt maximum added resistance and potential resistive imbalance between leads |
| Cost | Less expensive | More expensive |
| Complexity | Very simple and less subject to mechanical stress |
Physically larger and has a more complex construction making it more subject to mechanical stress |
| Calibration Ease | More difficult and adds CJC calibration |
Less difficult, no CJC to contend with |
| Noise Immunity | Lower noise immunity but often mitigated by good wiring practice. Small signals and high impedance leads can easily pick up noise. |
Better noise immunity than a T/C |
Nordson compatible heated hose are using both sensors as follows;
| Nordson® RTD Series Heated Hoses | Nordson® TC Series Heated Hoses | |
| Maximum Operating Temperature (°C ) |
232°C | 232°C |
| Maximum Hydraulic Pressure (psi) |
1000 psi | 1500 psi |
| Electrical Service | 120 VAC, 200 VAC, 240 VAC | 200 VAC, 230 VAC |
| Avaliable Lenghts | up to 20 meter | up to 13 meter |
