4-20mA – 3 wires

3 wires

The only advantage of 3-wire technology is that higher ohmic loads are possible, i.e., the current loop can also be operated on a measuring instrument of relatively high input impedance. Conclusion: With the exception of a high ohmic load requirement, 4-20 mA in 2-wire technology offers the user clear advantages- also over other signals, such as 0-10 V.