The Steinhart-Hart equation is a polynomial formula used to calculate an NTC thermistor's temperature versus its resistance relationship. This equation is probably the best option for describing the relationship between RvT, which calculates NTC thermistors. The Steinhart-Hart equation is more reliable and accurate over a wide range of temperatures when compared to beta calculations.
John Steinhart and Stanley R. Hart are the two individuals that created the equation (1968). The equation was first published in their article "Calibration Curves for Thermistors, Deep-Sea Research, and Oceanographic Abstracts. The two scientists/researchers met while working with the American Geophysical Union. Later the two moved to the Carnegie Institute of Washington, where they worked closely to develop the Steinhart-Hart equation. Since first published in the late 60s, the equation has been used to calculate the resistance in many of the products we use daily. The equation is an integral part of ensuring the NTC thermistor runs optimally.
Steinhart - Hart Equation = 1/T = A+B(LnR)+C(LnR)3
T = Temperature (Kelvin)
LnR =Natural log of measured resistance (NTC thermistor)
A, B, & C = Coefficients used for the equation (numbers vary depending on the model and style of the NTC thermistor. Range of temperature is also an important factor).
Variants of the above equation are designed to solve for the coefficients. Figuring out the coefficients allows users to implement the Steinhart-Hart equation in two separate ways, which includes:
a) When the temperature is known, and they need to calculate the expected resistance
b) When resistance is known and temperature is the desired reading
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