Steinhart-Hart Equation Calculator

The Steinhart-Hart equation is a widely used mathematical model that describes the relationship between temperature and resistance in NTC (Negative Temperature Coefficient) thermistors. It provides a more accurate temperature-resistance relationship than simpler models like the beta parameter equation, particularly over wide temperature ranges. These coefficients are typically determined by measuring the resistance at three different temperatures and solving the resulting system of equations, and are specific to each thermistor. Thermistors are commonly used in temperature sensing applications in scientific instruments, medical devices, and precision temperature control systems due to their high sensitivity to temperature changes. This calculator allows you to convert between temperature and resistance using the Steinhart-Hart equation, making it valuable for thermistor calibration and temperature measurement applications.

Formula

Steinhart-Hart equation: $$T = \frac{1}{A + B \ln(R) + C [\ln(R)]^3}$$

Where:

  • $T$ is temperature in Kelvin
  • $R$ is resistance in Ohms
  • $A$, $B$, and $C$ are calibration coefficients specific to the thermistor

For resistance from temperature: $$R = e^{\left(\frac{-B \pm \sqrt{B^2 - 4A(C-\frac{1}{T})}}{2C}\right)^{\frac{1}{3}}}$$

Steinhart-Hart Coefficients
The pre-entered values are typical for the thermistor included in the Thorlabs DBR780PN. Yours will likely differ.
Conversion mode
Temperature Input
Results Enter values to compute.
Temperature-Resistance Plot
Reference Table
Calculated resistance values for common laser operating temperatures:
Temperature Resistance