temperature
Type K Thermocouple vs PT100 RTD — Temperature Sensor Selection Guide
Type K thermocouples and PT100 RTDs are the two most common temperature sensors in Thai industry. Type K excels at wide temperature range (up to +1260°C), low cost, and fast response — but drifts more. PT100 delivers 4× better accuracy in the -200 to +400°C range with superior long-term stability, making it the choice for GMP and laboratory applications.
| Details | Generic / Multi-brand Type K Thermocouple (Chromel-Alumel) Type K | Generic / Multi-brand PT100 RTD Temperature Sensor PT100 |
|---|---|---|
| Starting Price | ฿350+ | ฿800+ |
| Range | -200–1260 °C | -200–850 °C |
| Accuracy | ±1.5°C (Class 1) / ±2.5°C (Class 2) | ±(0.15 + 0.002|T|)°C (Class A) |
| Connector | Miniature or standard K-type connector | - |
| Sensitivity | ~41 µV/°C (at 250 °C) | - |
| Temperature Range | -200 to +1260 °C | -200 to +850 °C |
| Accuracy (Class 1) | ±1.5°C or ±0.004|T| (whichever is greater) | - |
| Accuracy (Class 2) | ±2.5°C or ±0.0075|T| | - |
| Reference Standard | IEC 60584-1, ASTM E230 | - |
| Standard | - | IEC 60751, DIN EN 60751 |
| Alpha Coefficient | - | 0.00385 Ω/Ω/°C (IEC 60751) |
| Accuracy (Class A) | - | ±(0.15 + 0.002|T|) °C |
| Accuracy (Class B) | - | ±(0.30 + 0.005|T|) °C |
| Reference Resistance | - | 100 Ω at 0 °C |
Our Verdict
Choose Type K for furnaces, high-temperature processes, and budget-constrained applications. Choose PT100 for GMP environments, cold rooms, incubators, and any process requiring uncertainty below ±1°C.
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