Steinhart-Hart Approximations for Thermistor

​
Steinhart-Hart approximation
beta
temperatures
first
25
second
50
third
80
fourth
100
temperature (°C)
resistance (ohms)
measurement 1
25.
10000.
measurement 2
50.
4158.
computed beta
3381.98
This Demonstration considers a full set of measurements of a negative temperature coefficient thermistor and lets you select the approximation method and the data points to be used for a corresponding version of the Steinhart–Hart approximation. The computed Steinhart–Hart coefficients are displayed along with a plot of the difference between the measured and approximated values (the temperature error).

Details

Specification of a negative temperature coefficient thermistor is commonly expressed in terms of the coefficients in a Steinhart–Hart approximation. There are three common sets of coefficients: the beta coefficient that is computed from two measurement data points at two specified temperatures, the three-coefficient approximation that requires three measured data points and the four-coefficient approximation that requires four data points for curve fitting.
Two coefficients (beta constant):
R=
R
0
expβ·
1
T
-
1
T
0
Three coefficients (Steinhart–Hart equation):
1
T
=A+B·lnR+C·
3
ln
R
Four coefficients (Steinhart–Hart equation):
1
T
=A+B·lnR+C·
2
ln
R+D·
3
ln
R
A
,
B
,
C
and
D
are Steinhart–Hart coefficients and
β
is a constant commonly specified for thermistors. The coefficients for fitting the four-coefficient equation are not necessarily the same as those for fitting the three-coefficient equation.
R
is the thermistor resistance in ohms at temperature
T
.
T
is the thermistor temperature in degrees Kelvin.
T
0
is a reference temperature used for one of the measured data points used to calculate the
β
constant. Commonly, this is 25 °C.
R
0
is the thermistor resistance at the reference temperature
T
0
.
The measured data[1] is taken from the manufacturer's data for the model TDK part number NTCG063JF103FTDS.

References

[1] "NTCG063JF103FTDS." TDK Product Center. (Aug 6, 2021) product.tdk.com/en/search/sensor/ntc/chip-ntc-thermistor/info?part_no=NTCG063JF103FTDS.

Permanent Citation

Kirby Goulet
​
​"Steinhart-Hart Approximations for Thermistor"​
​http://demonstrations.wolfram.com/SteinhartHartApproximationsForThermistor/​
​Wolfram Demonstrations Project​
​Published: August 18, 2021