LJ18A3-8-Z/DX Inductive Proximity Sensor, 2-Wire DC NC, 6–36V, 6.4mm Detection Range

The LJ18A3-8-Z/DX is a Normally Closed (NC) type. In its resting state (no target present), the output circuit is closed, allowing current to flow. When a metal target enters the 6.4mm sensing range, the output switches to an open state, interrupting the current. This logic is ideal for safety circuits or applications requiring an active signal during normal operation.

No. Standard inductive proximity sensors like the LJ18A3 series are specifically tuned for ferrous metals (iron and steel). The sensing distance is significantly reduced or may be non-existent for non-ferrous metals like aluminum, brass, or copper. For non-ferrous detection, a capacitive or specialized inductive sensor is required.

Connect the brown wire to the positive DC supply voltage (6-36V) and the blue wire to the PLC's digital input common (typically 0V). The sensor acts as a switched load. Ensure your PLC input is configured as a sinking (NPN) type to complete the circuit through the sensor's NC contacts when no target is present.

This sensor features a shielded (flush-mountable) design. This means the sensing face and sides can be mounted flush with metal mounting brackets or surfaces without a reduction in the nominal sensing distance (6.4mm). Non-shielded sensors require a clear space around the sides to function correctly.

The sensor's solid-state output is rated for a maximum load current of 200 mA. Do not exceed this rating. It is designed to directly drive PLC inputs, small relays, or indicator lamps. For higher current loads, use an intermediate relay or contactor.