M12 Inductive Proximity Sensor NPN Normally Closed with 8mm / 10mm Non-flush

8 mm / 10 mm non-flush detection * 10-30 V DC * IP67 * 4-pin M12 connector

Models on this page: IN8-M12NC68-M0A/D, IN8-M12NC50-M0A/D, IN10-M12NC68-M0A/D, IN10-M12NC50-M0A/D

Normally-open sensors hide their faults. If the cable is cut, the connector is loose, or the supply drops, the PLC sees exactly the same state as "no metal present" -- and the line keeps running. The failure is silent until something crashes or a batch goes bad.

NPN normally-closed sensors invert that logic: the output is closed during normal operation, and any abnormal condition causes the output to disappear. The PLC detects "signal lost" and triggers a stop and an alarm. This is the fail-safe principle.

NPN output is current sinking. The internal NPN transistor has its emitter tied to 0 V (L−). The N.C variant inverts the logic of N.O:

• No metal target -> transistor on -> output pin is pulled to ~0 V, load is energized -> PLC input reads "1"
• Metal enters the range -> transistor off -> output pin goes high-impedance, load de-energizes -> PLC input reads "0"

The load is wired between L+ (brown, Pin 1) and OUT (black, Pin 4) -- the same wiring position as NPN N.O. Only the internal logic differs. When you retrofit an NPN N.O station with NPN N.C, the cabinet wiring stays as it is.

• IN8 series -- 8 mm detection range, 500 Hz switching -- faster response
• IN10 series -- 10 mm detection range, 400 Hz switching -- more installation margin

Both share the M12 × 1 mm cylindrical thread and non-flush (unshielded) installation. Same datasheet, same mounting logic.

• Normally-closed logic -- faults surface, not hide: During normal operation the output stays on. Cable break, M12 connector loose, 24 V supply lost, sensor itself failed -- any of these kills the output and the PLC captures it instantly. Turns "silent failure" into "loud alarm.
• Designed for safety interlocks and in-position checks: Safety gate closed -> metal flag enters the range -> output opens -> machine allowed to start. Gate opens -> output returns -> safety circuit acts. Same idea for confirming that a workpiece is still in the fixture (drop-out triggers the alarm).
• Same wiring as NPN N.O -- zero rewiring when you upgrade: The load is wired between L+ and OUT, exactly as on NPN N.O. Upgrading from N.O to N.C requires no wiring change -- only invert the input logic in the PLC program. Retrofit projects are particularly easy.
• NPN current-sinking, direct to Japanese PLCs: The output plugs straight into the sink input of Mitsubishi, Omron or similar modules -- no interposing relay.
• Two detection ranges on one page: Choose 8 mm at 500 Hz for high-speed applications, or 10 mm at 400 Hz when the target has more play.
• Non-flush (unshielded) -- longer range from the same M12 footprint: The unshielded structure lets the magnetic field spread sideways, giving a longer rated range than the flush variant. The trade-off is the free metal space around the sensing face -- see Configuration Details.
• IP67 + −25…70 °C: IP67 per IEC 60529: dust-tight and protected against temporary immersion. Operating temperature covers −25 °C cold storage to +70 °C cabinet-side mounting.
• Nickel-plated brass + PBT sensing face: Nickel-plated brass housing for impact and corrosion resistance. Blue PBT sensing face, wear-resistant and insensitive to metal swarf. Two hex nuts (17 mm across flats) resist long-term vibration loosening.
• Field-replaceable M12 connector + triple electrical protection: 4-pin M12 A-coded male connector (IEC 61076-2-101) for quick cordset replacement on the floor. Built-in short-circuit, reverse-polarity and power-up pulse protection -- the sensor survives commissioning mistakes.

Key point: The wiring position is identical to NPN N.O (load between L+ and OUT). Only the internal logic differs -- output is closed when no metal is present, and opens when metal arrives.

• Free metal space around the sensing face. Non-flush sensors let the magnetic field expand sideways. Without sufficient clearance, the effective range collapses. Recommended free space ≥ 3 × Sn (≈ 24 mm for the 8 mm body, ≈ 30 mm for the 10 mm body). Side-by-side sensors also need adequate spacing to prevent mutual interference.
• If you must flush-mount. This series is unshielded. Switch to a flush (shielded) variant if side clearance is impossible.
• Tightening torque. Suggested maximum 15 N*m to avoid housing deformation.
• Safety-point placement. Mount interlocks where they cannot be easily struck. Consider a protective bracket. Route the cable away from power conductors.

• Factory-measured values (cited directly from datasheet): operating voltage 10…30 V DC (±10%), voltage drop ≤ 2.0 V, operating current 200 mA, leakage current ≤ 0.01 mA, no-load current ≤ 10 mA (24 V), hysteresis < 15% Sr, repeat accuracy < 1.0% Sr, triple electrical protection, 4 × LED indication, −25…70 °C, IP67, brass nickel-plated + PBT, M12 connector, M12 × 1 mm thread, 8 mm / 10 mm non-flush, 500 Hz / 400 Hz, all dimensional values.
• Standard-derived values (datasheet not specified; per IEC 60947-5-2): response time, standard target (Fe37), correction factors for non-ferrous metals. Not stated on this page; request confirmation from engineering before publishing.
• Engineering guidance (not datasheet figures): free space ≥ 3 × Sn, nut torque ≤ 15 N*m. Labelled "suggested" in the text.
• Safety-rating statement: This series is not certified to ISO 13849 / IEC 62061. The notes above clearly mark this; no safety-rating claim is made.
• No invented content. This document contains no fabricated performance figures, customer case studies, sales figures, or certifications.