Pt100 vs Pt1000 RTDs: Key Differences Explained

This article explores the distinctions between Pt100 and Pt1000 Resistance Temperature Detectors (RTDs). Let’s dive in!

Introduction to RTDs

• RTD stands for Resistance Temperature Detector.
• RTDs have a positive temperature coefficient. This means their resistance increases as the temperature goes up.
• For relatively low temperatures, the relationship between resistance and temperature can be approximated by the formula: R_T = R_0 * (1 + α * ΔT)
• For higher temperatures, a different formula applies: R2 = R1 + R0 * α(t2 - t1)
  • Where α represents the resistance temperature coefficient, measured in units of /°C.
• Both Pt100 and Pt1000 RTDs are platinum resistance thermometers, relying on the resistance of a platinum element for temperature measurement.
• They provide excellent accuracy across a broad temperature range.
• Both are considered PTC (Positive Temperature Coefficient) type resistance thermometers.
• They are typically manufactured using thin-film technology.

Pt100 RTD

• The Pt100 RTD utilizes a platinum wire, carefully wrapped around a ceramic core.
• It shows a linear increase in resistance as temperature rises.
• At 0°C, the Pt100 offers a resistance of 100 Ohms.
• At 100°C, its resistance is about 138.4 Ohms.
• The sensitivity of a Pt100 is 0.391 Ohms per °C.

Pt1000 RTD

• Similar to the Pt100, the Pt1000 RTD also uses a platinum wire wrapped around a ceramic core.
• It also exhibits a linear relationship between resistance and temperature.
• The key difference is that Pt1000 offers resistance values that are ten times higher than those of a Pt100.
• The sensitivity of a Pt1000 is 3.91 Ohms per °C.

Key Differences Summarized

For further reading, you might find it useful to explore the differences between RTDs and thermocouples:

• RTD versus Thermocouple
• Advantages and Disadvantages of RTDs
• Advantages and Disadvantages of Thermocouples