Corrections, Why use corrections, Correction ids – Omega Engineering M-4066 User Manual
Page 61: Pre-defined thermistor, Soft-opc can see, Predefined corrections
OMWT-SOFT-OPC Server
Corrections N 57
Predefined Corrections
The device type "Thermistor" will default to a correction ID of 128. To override this
default you can add a CorrID parameter to the device section of the OMWT-SOFT-
OPC.INI file, or you can set a new default for all thermistors in the Server section of
the OMWT-SOFT-OPC.INI file. To change the default CorrectionID for all
thermistors add the parameter "DefaultThermistorCorrID=" to the Server section, and
set it to whatever CorrectionID you wish.
Predefined Corrections use the following equations. The first equation normalizes
the passed value, and the second produces the conversion to degrees Celsius.
Parameters:
NTC_DIVIDERES = 10000
NTC_NORMALRES = 10000
Fitting constants:
A = 3.3539264E-3
B = 2.5609446E-4
C = 1.9621987E-6
D = 4.6045930E-8
R
normal
= NTC_DIVIDERES / (32767 / value ) - 1 / NTC_NORMALRES
Value in degrees Celsuis = 1 / ( A + B*R
normal
+ C*R
normal
2
+
D*R
normal
3
)