DaqSense
Download Preview
Free Tool

Steinhart-Hart Coefficient Calculator

Generate calibration coefficients for NTC thermistors from three experimental measurements.

1. Calibration Points

Temp Unit:
Point 1 (e.g. Ice Bath)
Point 2 (e.g. Room Temp)
Point 3 (e.g. Boiling / Warm)

2. Computed Coefficients

Coefficient A
0.0000000e+0
Coefficient B
0.0000000e+0
Coefficient C
0.0000000e+0

3. Code & Config Exports

C / C++ ARDUINO SOURCE CODE
// Enter measurements and click calculate to generate code
DAQSENSE CALIBRATION IMPORT JSON
// Enter measurements and click calculate to generate config
DaqSense Desktop

Need saved calibration profiles and live sensor parsing?

DaqSense keeps calibration presets, parser rules, live engineering units, raw capture, and CSV exports together for repeatable hardware tests.

Learn More

Understanding the Steinhart-Hart Equation

The Steinhart-Hart equation is a highly accurate mathematical model representing the resistance-temperature behavior of semiconductor thermistors (specifically NTC, or Negative Temperature Coefficient thermistors). It is defined as:

1T=A + B ln(R) + C (ln(R))3

where:

  • T is the absolute temperature in Kelvin (K = °C + 273.15).
  • R is the measured resistance at temperature T in Ohms (Ω).
  • A, B, and C are the device-specific Steinhart-Hart coefficients.

Why Use Steinhart-Hart Instead of Beta (β)?

Many basic electronics tutorials use the simplified Beta Parameter equation to convert resistance to temperature. While simpler, the Beta parameter assumes a linear relationship between log-resistance and inverse-temperature, which holds true only over very narrow ranges (e.g. 0°C to 50°C).

The Steinhart-Hart equation introduces the third-order logarithmic term (ln(R))3, correcting for sensor non-linearity across the thermistor's full operating range (typically -40°C to 125°C), reducing interpolation errors to less than 0.02°C.

How to Record Your Calibration Points

To calculate your thermistor's unique coefficients, you must measure its resistance at three distinct, widely spaced temperature points. For maximum accuracy:

  1. Ice Bath Point (Low Temperature, e.g., 0°C): Submerge the thermistor in a thermos filled with crushed ice and a minimal amount of distilled water. Measure the exact resistance once stabilized.
  2. Room Temperature Point (Mid Temperature, e.g., 25°C): Keep the thermistor in a temperature-controlled room alongside a calibrated reference thermometer.
  3. Warm/Hot Water Point (High Temperature, e.g., 75°C - 100°C): Submerge the thermistor in heated water. Measure the resistance alongside a reference thermometer.

Tip for DaqSense Users: You can copy the generated JSON import block above and load it directly into your DaqSense calibration preset library to configure your physical USB channels instantly.