Eaton XN300 - 26.3 Measurement ranges

26 Analog input module XN-322-10AI-TEKT
26.2 Wiring topic
XN300 slice modules 02/24 MN050002EN Eaton.com 194
26.2.3 Measurement ranges
The readings are represented as a decimal value in °C with one decimal place
(in 1 / 10 °C)
Table 14 Measurement ranges and measurement errors
26.2.4 How measurement errors are calculated
Aside from the length of the corresponding input wiring, a thermocouple's
loop resistance depends on the cross-sectional area of said input wiring and
on the material being used.
Say you have a type K thermocouple with a cross-sectional area of 0.22 mm
2
and a loop resistance of 4.5  / m (the loop resistance can be found in the
data sheet for the thermocouple being used).
In order to calculate the measurement error, you would use the following
formula:
As per table  Table 14, the measurement error for type K = 0.0077 % / .
Relative to a measurement range with 940 °C, you would get a
measurement error of 0.33 °C/m.
The error can be reduced by using a thermocouple with a larger
cross-sectional area.
Catalog
Number
Thermocouple Measuring range
[°C]
Measuring range
[mV]
Measured
value
1)
[1/10°C]
Measurement
error
2)
[%/Ω]
Resistance
J Fe-CuNi -10 … +690 °C -0.501…38,512 -100…+6900 0.0078
K NiCr-Ni -40…+940 °C -1,527…38,918 -400…+9400 0.0077
T Cu-CuNi -40…+400 °C -1,475…20,872 -400…4+000 0.0144
E NiCr-CuNi 0…+520 °C 0…38,624 0…+5200 0.0078
N NiCrSi-NiSi -80… +1080 °C -1,972…+39,326 -800…+10800 0.0076
S Pt10Rh-Pt -50…+1760 °C -0.236…+18,609 -500…+17600 0.0161
R Pt13Rh-Pt -50… +1760 °C -0.226…+21,003 -500…+17600 0.0142
B Pt30Rh-Pt6Rh 0… +1820 °C 0…+13,820 0…+18200 0.0217
L Fe-CuNi 0…+680 °C 0…+38,487 0…+6800 0.0078
U Cu-CuNi 0…+590 °C 0…+33,606 0…+5900 0.0089
KTY10 – -20 °C… +80 °C 1367…2980 
1) If the input is open, the hardware class will deliver a value of -2147483632
2) Measurement error resulting from the thermocouples' cable resistance relative to the measurement range
Measurement
error
[940°C]
=
0.0077
1
* 4.5

* 940 °C = 0.33
°C

m
m