Keithley SourceMeter 2790 Reference Manual page 506

Model 2790 SourceMeter® Switch System Reference Manual
Converting K to °C — The temperature in Kelvin can be converted to °C as follows:
T = T
°C
where: T
Example — Calculate the temperature for a Series 44007 thermistor that measures 5kΩ
(R):
lnR = ln(5000) = 8.5172
A = 0.001288
B = 0.0002356
C = 9.557e-8
T
K
T
°C
- 273.15
K
is the temperature in °C.
°C
T is the calculated Kelvin temperature.
K
= 1 / {A + (BlnR) + [(C)(lnR)
= 1 / {0.001288 + [(0.0002356)(8.5172)] + [(9.557e-8)(8.5172
= 1 / (0.001288 + 0.002007 + 0.000059)
= 1 / 0.003354
= 298.15
= T - 273.15
K
= 298.15 - 273.15
= 25°C
3
]}
E-3
3
)]}