RTD Formula Calculator

What is an RTD?

An RTD (Resistance Temperature Detector) is a sensor used to measure temperature by correlating the resistance of the RTD element with temperature. RTDs are known for their accuracy and stability over a wide temperature range. They are commonly used in industrial applications where precise temperature measurements are required.

Formula

The formula to calculate the resistance at a specific temperature for an RTD is:

\[ R_t = R_0 (1 + \alpha (T - T_0)) \]

Where:

\( R_t \) is the resistance at temperature \( T \) (Ω).
\( R_0 \) is the base resistance at reference temperature \( T_0 \) (Ω).
\( \alpha \) is the temperature coefficient of resistance (°C⁻¹).
\( T \) is the temperature at which resistance is measured (°C).
\( T_0 \) is the reference temperature, usually 0°C for calculations.

Example

Let's say the base resistance is 100 Ω, the temperature coefficient is 0.00385 °C⁻¹, the temperature is 100 °C, and the reference temperature is 0 °C. Using the formula:

\[ R_t = 100 (1 + 0.00385 (100 - 0)) \]

We get:

\[ R_t = 100 (1 + 0.385) = 100 (1.385) = 138.5 \]

So, the resistance at 100 °C (\( R_t \)) is 138.5 Ω.