Siemens Desigo TRA Engineering, Mounting And Installation Manual page 36

Measured value error
T1 sensors
Key
Measured value error
NTC sensor
Measured value error
Resistance transmitters
Key
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Siemens
Building Technologies
T1 sensors: Measured value error due to line resistance:
F [K]
0,6 mm Ø
1.0
0.8
0.6
0.4
0.2
0
-0.1 100
2 L
57 A
Formula: F =
10
A Cable cross-section in mm
F Measured temperature error in K
L Cable length in m
Measured value error of NTC sensors due to line resistance:
The sensors are highly non-linear. But thanks to the high sensor resistance the
errors are very small.
Error compared to T1:
NTC 100K
20°C x 0.01
100°C x 0.1
Resistance transmitters (potentiometers):
Measured value error due to line resistance
F [Ohm]
0,6 mm Ø
8
6
4
2
0
-1 100
2 L
Formula: F =
57 A
A Cable cross-section in mm
F Measurement error in ohms, due to line resistance (2RL for supply and return
conductor)
L Cable length in m
Desigo TRA Engineering, mounting and installation
Wiring of field devices (without bus)
1 mm
200
1
2
NTC10K NTC3K
x 0.1 x 0.3
x 1 (~ equal) - -
²
1 mm
1,5 mm
2,5 mm
200 300
L [m]
1
2
²
²
1,5 mm
²
2,5 mm
300
L [m]
²
²
CM111043en_09
2016-02-22