How to Measure 4 to 20 mA Output from a 2-Wire Sensor
A 2-wire sensor having 4 to 20 mA output is a device equipped with both a power supply line and 4 to 20 mA output through its circuit configuration that changes the current consumption of the power supply line in the range of 4 to 20 mA. This section introduces wiring for measurement and a key point in selecting a 2-wire sensor.
Wiring and key point in selection
A 2-wire sensor enables you to reduce wiring work because it requires only a small number of wires. The measurement of 4 to 20 mA is performed by inserting a load resistance into a power supply line, thereby converting the load resistance to voltage.
Wiring
Key point in selection
- Satisfy the relationship of “maximum load resistance of the 4 to 20 mA output > load resistance (shunt resistor).”
