PT RTD Calculator

Jul 21, 2022

T_min:

T_max:

V_cc:

R₀ @ 0°C:

R₁:

R₂:

R₃:

drawing

$$ V_{off} = V_{cc} \cdot \frac{R_2}{R_1 + R_2} $$

$$ V_p = V_{cc} \cdot \frac{R_{pt}//R_3}{R_1 + R_{pt} // R_3} $$

$$ G = \frac{R_3}{R_1//R_2} + 1 $$

$$ V_{out} = G(V_p - V_{off}) + V_{off} $$

The PT RTD follows the Callendar-Van Dusen Equation. Click the link for a good explanation of RTD sensors.

The equation goes as follows. For temperatures less than 0°C

$$ R_{pt}(T) = R_0 \cdot \Bigl(1 + AT + BT^2 + \bigl(CT^3 \cdot (T - 100)\bigr) \Bigr)$$

and for temperatures above 0°C

$$ R_{pt}(T) = R_0 \cdot \bigl(1 + AT + BT^2 \bigr) $$

Where

$$A = 3.9093e-3 $$ $$B = -5.775e-7 $$ $$C= -4.183e-12 $$