Thermistor Resistance To Temperature Calculator

Steinhart-Hart Equation:

\[ T = \frac{1}{A + B \ln R + C (\ln R)^3} - 273.15 \]

A (constant, 1/K):

B (constant, 1/K):

C (constant, 1/K):

R (resistance):

ohms

Temperature (T):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is the Steinhart-Hart Equation?

The Steinhart-Hart equation is a model used to calculate the temperature of a thermistor from its resistance. It provides a more accurate temperature-resistance relationship than simpler models, especially over wide temperature ranges.

2. How Does the Calculator Work?

The calculator uses the Steinhart-Hart equation:

\[ T = \frac{1}{A + B \ln R + C (\ln R)^3} - 273.15 \]

Where:

\( A, B, C \) — Thermistor-specific constants (1/K)
\( R \) — Measured resistance (ohms)
\( T \) — Calculated temperature (°C)

Explanation: The equation models the non-linear relationship between a thermistor's resistance and temperature using a third-order polynomial approximation of the natural logarithm of resistance.

3. Importance of Temperature Calculation

Details: Accurate temperature measurement from thermistor resistance is crucial for temperature sensing applications in various fields including industrial processes, environmental monitoring, medical devices, and consumer electronics.

4. Using the Calculator

Tips: Enter the thermistor-specific constants A, B, and C (typically provided in the datasheet), and the measured resistance in ohms. The resistance value must be positive.

5. Frequently Asked Questions (FAQ)

Q1: Where do I find the A, B, C constants for my thermistor?
A: These constants are typically provided in the thermistor's datasheet. They are specific to each thermistor model and are determined through calibration.

Q2: Why use Steinhart-Hart instead of simpler models?
A: The Steinhart-Hart equation provides higher accuracy over wider temperature ranges compared to simpler beta parameter or linear approximations.

Q3: What temperature range is this equation valid for?
A: The equation is typically accurate across the thermistor's specified operating range, usually from -50°C to 150°C for most thermistors.

Q4: Why subtract 273.15 in the equation?
A: The Steinhart-Hart equation originally returns temperature in Kelvin. Subtracting 273.15 converts Kelvin to Celsius.

Q5: Can this calculator handle negative temperatures?
A: Yes, the calculator can calculate negative temperatures (below 0°C) as long as the input values are valid and the resistance measurement is accurate.