10
Voltage measurement
Long signal paths can be a problem when transmitting
voltage signals (cable resistance, interference etc.).
It is advisable to use current signals for safe
transmission (4 to 20 mA).
Shunt resistances between 50
Ω
or 500
Ω
(50
Ω
: 0.2 to
1 V, 500
Ω
: 2 to 10 V) are parallel connected to the
multimeter, controller etc. when measuring voltage (0.2
to 1 V, 2 to 10 V) (see Figure).
Advantage
- Reliable signal due to power transmission
- Recognises disconnected cable (“live zero”)
Voltage measurement from 2 to 10 V or 2 to 10 V is
not possible in instruments with displays H1, H3, H7
since they are loop-fed.
Connection suggestions
for 2 wire technology
4
3
2
1
Transmitter
0.2...1V (2...10V) = -20...+70 °C
0.2...1V (2...10V) = 0...+100 %RH
50
Ω
(500
Ω
)
50
Ω
(500
Ω
)
%RH
