NTC Resistance to Temperature Calculator Based on Steinhart-Hart Equation

Steinhart-Hart Equation:

\[ T = \frac{1}{A + B \ln(R) + C (\ln(R))^3} \]

Resistance (R):

Coefficient A:

1/K

Coefficient B:

1/K

Coefficient C:

1/K

Temperature (Kelvin):

Temperature (Celsius):

Temperature (Fahrenheit):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is the Steinhart-Hart Equation?

The Steinhart-Hart equation models the resistance-temperature relationship of NTC (Negative Temperature Coefficient) thermistors. It provides a more accurate temperature calculation than simpler beta parameter equations, especially over wide temperature ranges.

2. How Does the Calculator Work?

The calculator uses the Steinhart-Hart equation:

\[ T = \frac{1}{A + B \ln(R) + C (\ln(R))^3} \]

Where:

\( T \) — Temperature in Kelvin
\( R \) — Measured resistance in ohms (Ω)
\( A, B, C \) — Thermistor-specific coefficients

Explanation: The equation accounts for the non-linear relationship between resistance and temperature in NTC thermistors.

3. Importance of NTC Thermistors

Details: NTC thermistors are widely used for temperature sensing due to their high sensitivity, fast response times, and small size. Accurate temperature calculation is essential for applications like medical devices, automotive systems, and environmental monitoring.

4. Using the Calculator

Tips: Enter the measured resistance in ohms and the thermistor's A, B, and C coefficients (typically provided in the datasheet). Default values are provided for a common NTC thermistor.

5. Frequently Asked Questions (FAQ)

Q1: Where do I find the A, B, C coefficients?
A: These are typically provided in the thermistor's datasheet. For common 10K thermistors, the default values in this calculator are often used.

Q2: How accurate is the Steinhart-Hart equation?
A: It's typically accurate to ±0.1°C or better over the thermistor's operating range, much better than simpler beta parameter equations.

Q3: What's the difference between NTC and PTC thermistors?
A: NTC (Negative Temperature Coefficient) thermistors decrease resistance with increasing temperature, while PTC (Positive Temperature Coefficient) thermistors increase resistance with temperature.

Q4: Can I use this for RTDs?
A: No, RTDs (Resistance Temperature Detectors) use different equations (usually Callendar-Van Dusen) as they have a more linear response.

Q5: Why does the equation use Kelvin?
A: The equation was derived using absolute temperature (Kelvin), though results can be converted to Celsius or Fahrenheit.