What is an RTD?
An RTD is a resistance temperature detector: a metal element, usually platinum, whose resistance rises with temperature in a known way.
RTD Explained
Platinum RTDs are accurate, stable and close to linear, so they are the standard for process temperatures up to about 600 °C. The common element is Pt100, 100 Ω at 0 °C.
Elements are wire wound or thin film. Lead wire resistance must be compensated with 3 or 4 wire connections.
RTD: Typical Values
| Pt100 at 0 °C | 100.00 Ω |
| Pt100 at 100 °C | 138.51 Ω |
| Typical range | about −200 to 600 °C |
Calculators for RTD
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Frequently Asked Questions
What is an RTD?
An RTD is a resistance temperature detector: a metal element, usually platinum, whose resistance rises with temperature in a known way.
RTD or thermocouple?
RTDs are more accurate and stable below about 600 °C; thermocouples cover higher temperatures, respond faster and are more robust.
What is a Pt1000?
A platinum RTD with 1000 Ω at 0 °C; it reduces lead wire error and is common with 2 wire connections.
Learn more on the blog
What is an RTD and how it works
A practical guide on instrumentationblog.in with more detail on RTD and how it is applied on real plants.
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