Callendar-Van Dusen Equation
Platinum RTDs use a linearization curve known as the Callendar-Van Dusen equation to measure the temperature of RTDs. The equation is as follows:
Temperatures below 0 °C:
RT = R0[1 + A × T + B × T2 + C × T3 × (T – 100 °C)]
Temperatures above 0 °C:
RT = R0[1 + A × T + B × T2]
T = temperature in degrees Celsius
RT = RTD resistance at temperature T
R0 = RTD nominal resistance at 0 °C
A, B, and C = coefficients given in the table in RTD Types.