Capgo datalogger, data logger, datalogging and data logging.




Thermistor Calculator

Below is the Capgo Thermistor Calculator.

The calculator is initialized with calibration coefficients of the popular YSI 44004 thermistor

To use it you need a browser that supports Java applets.




The calculator is multifunctional and bidirectional, allowing you to:

  • select your preferred temperature units
  • select a predefined thermistors by manufacturer's part number OR
  • calculate the calibration coefficients from three calibration points OR
  • direct entry of the calibration coefficients from manufacturer's data
  • calculate the temperature from the thermistor's measured resistance
  • calculated the thermistor's resistance from its temperature



The calibration coefficients correspond to a, b and c in the Steinhart & Hart equation:

T = 1 / ( a + b.ln(R) + c.ln(R)3)

where the temperature T is always converted to degrees Kelvin and the resistance R is in ohms. When using the calibration feature of the calculator, ensure the temperatures of the three calibration points are approximately equally spaced, and cover the range over which the sensor will be used.

Note, the calculator uses the values as seen on the display. The output is rounded to 0.1°C and 0.01 Ohms, so when an output is subsequently used as an input, the result will reflect this rounding - it may be a little different to the original input.