5.12. 4
– 20mA % measurements
4 - 20 mA circuits represent an analog electrical transmission
standard for industrial instruments and the communication. In such a
circuit, a level corresponding to 0% of 4 mA and 20 mA, a level of
100% of the signal. The zero position at 4 mA allows the receiving
instrument to distinguish between a zero signal and a broken wire or
faulty appliance. The advantage of the 4-20 mA transmission are low
implementation costs and the possibility of excluding many forms of
electrical noise.
1. Set up and connect as described for DC mA measurements.
2. Set the rotary function sw
itch to the “4-20mA%”-position.
3. The meter will display loop current in % as follows:
0 mA
-25%
4 mA
0%
20 mA
100%
24 mA
125%
-95-
