Stainless-Steel Pepperl+Fuchs NCB5-18GM40-N0 NAMUR Inductive Sensor with 5 mm Flush Detection

Pepperl+Fuchs NCB5-18GM40-N0 is an M18 inductive proximity sensor for detecting metal targets without mechanical contact. It provides a 5 mm rated operating distance in a flush-mount design, uses a two-wire NAMUR normally closed output, and is supplied in a compact stainless-steel housing. The model is suitable for hazardous-area automation when it is connected to an approved isolated barrier or switching amplifier and installed according to the applicable certification.

The Important Details Are in the Complete Code

NCB5 identifies the sensor family and nominal sensing range, while 18GM40 describes the M18 cylindrical housing and compact body length. N0 indicates the NAMUR normally closed electrical function. Cable-length and connector variants add further suffixes, so the installed label must be checked before ordering. A sensor that looks identical may have a different output type, cable length, connector, or switching function.

Key Product Data

• Rated operating distance: 5 mm
• Installation: flush in metal
• Output: two-wire NAMUR, normally closed
• Nominal operating condition: 8.2 V with approximately 1 kOhm source resistance
• Switching frequency: up to 400 Hz
• Housing: stainless steel, M18 diameter
• Protection degree: IP66/IP67
• Published ambient range: -25 °C to +100 °C
• Functional safety capability: usable up to SIL 2 when applied as specified

NAMUR sensors do not connect directly to a standard 24 V DC digital input. The NCB5-18GM40-N0 must be used with a compatible interface that supplies the correct low-energy circuit and interprets the NAMUR current levels. The barrier or amplifier also determines relay logic, line fault detection, and safe-area output behavior.

Mechanical Fit Matters as Much as Electrical Fit

Flush installation allows the sensing face to be mounted level with surrounding metal, but the target material and target size still influence the usable switching distance. Published reduction factors show that aluminum, copper, and stainless steel may be detected at a shorter distance than the standard steel target. During replacement, preserve the original mounting position and verify the real operating gap rather than relying only on the nominal 5 mm value.

Check cable routing, bend radius, connector or fixed-cable version, and exposure to heat, vibration, oil, or mechanical damage. The sensing face must remain clear of metal debris that could cause a permanent detected condition.

Replacement Checklist

1. Read the full label, including any cable-length or connector suffix.
2. Confirm NAMUR normally closed operation.
3. Verify flush mounting and the actual target gap.
4. Check the connected barrier model and required fail-safe logic.
5. Test target present, target absent, open circuit, and short circuit.
6. Confirm the hazardous-area approval for the installation location.

Typical uses include valve position feedback, actuator travel detection, conveyor monitoring, machine position sensing, speed targets, and end-position detection in chemical, oil and gas, pharmaceutical, food, water-treatment, marine, and general automation systems.

For quotation, provide the exact NCB5-18GM40-N0 code, quantity, required cable or connector version, destination, and delivery deadline. Sunup-MTL supports Pepperl+Fuchs sensor and isolated-barrier sourcing, model checks, export packing, and international shipment.

Related Pepperl+Fuchs NCB5 and M18 NAMUR Sensor Models

The models below cover the principal NCB5-18GM40 connection and cable-length variants, plus closely related M18 NAMUR sensors. Check sensing distance, flush or non-flush mounting, output function, cable length, connector type, approval, and ambient-temperature requirements before substitution.