What does RTD stand for and how does it measure temperature?

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Multiple Choice

What does RTD stand for and how does it measure temperature?

RTD stands for Resistance Temperature Detector. It measures temperature by watching how the electrical resistance of a metal changes as temperature changes. In practice, a small length of metal, most often platinum, is used because its resistance versus temperature is very stable and predictable. As temperature rises, the metal’s atoms vibrate more and scatter electrons more, increasing resistance in a nearly linear way over a useful range. The relationship is described by R = R0[1 + α(T − T0)] for many applications, with more exact equations used for high-precision work (like the Callendar-Van Dusen model for platinum). To get an accurate temperature reading, RTDs are often wired in a Wheatstone bridge or measured with a precise ohmmeter; four-wire connections are common to cancel out lead resistance. This makes RTDs highly accurate and stable, which is why they’re favored in critical locations. Common RTD types include Pt100 or Pt1000, where the resistance at 0°C is 100 ohms or 1000 ohms, respectively. RTDs are preferred over polymer-based sensors when you need good linearity, repeatability, and long-term stability.

RTD stands for Resistance Temperature Detector. It measures temperature by watching how the electrical resistance of a metal changes as temperature changes. In practice, a small length of metal, most often platinum, is used because its resistance versus temperature is very stable and predictable. As temperature rises, the metal’s atoms vibrate more and scatter electrons more, increasing resistance in a nearly linear way over a useful range. The relationship is described by R = R0[1 + α(T − T0)] for many applications, with more exact equations used for high-precision work (like the Callendar-Van Dusen model for platinum).

To get an accurate temperature reading, RTDs are often wired in a Wheatstone bridge or measured with a precise ohmmeter; four-wire connections are common to cancel out lead resistance. This makes RTDs highly accurate and stable, which is why they’re favored in critical locations. Common RTD types include Pt100 or Pt1000, where the resistance at 0°C is 100 ohms or 1000 ohms, respectively. RTDs are preferred over polymer-based sensors when you need good linearity, repeatability, and long-term stability.

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