© National Instruments Corporation 7 SCC-TC Series Thermocouple Input Modules User Guide
You can use the following formulas to convert the cold-junction sensor
voltage to cold-junction temperature:
where TK is the temperature in kelvin.
where
a = 1.295361 × 10–3
b = 2.343159 × 10–4
c = 1.018703 × 10–7
RT is the resistance of the thermistor in ohms.
where VTEMPOUT is the output voltage of the cold-junction sensor.
where T(°F) and T(°C) are the temperature readings in degrees Fahrenheit
and Celsius, respectively.
Note VTEMPOUT varies from 1.91 V (at 0 °C) to 0.58 V (at 55 °C). For best resolution, use
the maximum gain for this range on the analog input channel.
For the cold-junction sensor measurement accuracy, refer to the
Specifications section.
Uncompensated Connectors and AccuracyIf you are using an SCC-TC02 with an uncompensated SCC panelette,
temperature gradients between the module and the junctions on the
panelette affect the accuracy of your measurements.
T°C() TK273.15–=
TK
1
ab Rln T
()cRln T
()
3
++[]
--------------------------------------------------------------=
RT5000
VTEMPOUT
2.5 VTEMPOUT
–
--------------------------------------
,=
T°F() T°C()]9[
5
------------------------32+=