Generic LJ12A3-4-Z/BY Inductive Proximity Sensor - NPN NO Output, 4mm Range, 1.15m Cable

This is a 3-wire sensor: Brown wire connects to DC positive supply (6-36V), Blue wire connects to DC negative/common ground, and Black wire is the NPN output. The Black output wire switches to ground (sinks current) when a metal target is detected within the 4mm range.

Yes, inductive proximity sensors detect all conductive metals, but the sensing distance is reduced for non-ferrous metals compared to steel. For this 4mm nominal model, the effective sensing distance for aluminum is typically 30-50% shorter. Always test with your specific target material.

The 300mA rating is the maximum continuous current the sensor's internal transistor can sink. You can directly drive PLC inputs, relay coils, or indicator lamps within this limit. For inductive loads like relays, use a flyback diode across the coil to protect the sensor from voltage spikes.

Mount the sensor securely so the metal sensing face is parallel to the target surface. The 4mm sensing distance is fixed and non-adjustable. Ensure there is no other metal within this range to avoid false triggering. Maintain a clearance of at least one sensor diameter from surrounding metal for stable operation.