Product Description

SICK WT150-N460 — W150 Miniature Photoelectric Sensor, Background Suppression, NPN Output

A sensor that reacts to the background instead of the target is worse than no sensor at all. Background suppression was developed specifically to solve this problem — and the WT150-N460 applies it in one of the most compact housings in the SICK W150 range. At just 10 × 28 × 18 mm and 7 grams, this sensor fits into machine frames and conveyor arrangements where larger units simply don't fit, while reliably detecting objects from 2 mm to 100 mm away without responding to whatever is behind them.

New sealed. Part number 6011047. In stock and available for immediate worldwide dispatch.

Technical Specifications

Parameter	Value
Part Number	6011047
Type	WT150-N460
Product Family	W150 Miniature Photoelectric Sensors
Functional Principle	Photoelectric proximity sensor
Detection Method	Background suppression (BGS)
Sensing Range	2–100 mm ¹⁾
Focus / Dispersion Angle	Approx. 5°
Light Type	Visible red light
Light Source	LED (avg. service life 100,000 h @ +25°C)
Sensitivity Adjustment	5-turn potentiometer
Supply Voltage	10–30V DC
Ripple	±10%
Current Consumption	20 mA (without load)
Switching Output	NPN
Switching Mode	Light switching / Dark switching
Switching Mode Selector	Selectable via L/D control cable
Output Current (max)	≤ 100 mA
Response Time	≤ 0.5 ms
Switching Frequency	1,000 Hz
Connection Type	Male connector M8, 4-pin
Circuit Protection	Reverse polarity (VS), reverse polarity (I/O), interference suppression, overcurrent/short-circuit
Protection Class	II
Enclosure Rating	IP67
Housing Material	Plastic, ABS
Optics Material	Plastic, PC
Dimensions (W × H × D)	10 × 28 × 18 mm
Weight	7 g
Ambient Operating Temp.	−25°C to +55°C
Storage Temperature	−40°C to +75°C
LED Indicators	Green (stability), Orange (output active)
Items Included	BEF-W150-A mounting bracket
MTTFD	1,686 years
DCavg	0%
UL File No.	NRNT2.E128350 & NRNT8.E128350

¹⁾ Object with 90% remission based on standard white, DIN 5033.

Background Suppression: Detecting the Object, Not the Scene

Standard diffuse-mode photoelectric sensors measure the total reflected light in their field of view. When the background is highly reflective — a white wall behind a dark conveyor belt, a bright machine frame behind a small part — a diffuse sensor can trigger on the background rather than the target. Repositioning the sensor helps only so far; the problem is geometric, not just optical.

Background suppression solves this by using triangulation rather than total light intensity. The WT150-N460 contains both an emitter and a receiver positioned so that the angle at which reflected light returns to the receiver encodes the distance of the reflecting object. Objects at the set sensing range return light at the expected angle and trigger the output. Objects beyond the set range — backgrounds, walls, conveyor surfaces — return light at a different angle and are ignored, regardless of how reflective they are.

The result is detection that is genuinely object-selective rather than scene-selective. A black component on a white background, or a white label on a silver foil package, can both be detected reliably with the sensing range set appropriately for the target.

The 5-Turn Potentiometer: Precision Range Setting on the Sensor

The sensing range of the WT150-N460 is not fixed — it is adjustable from 2 mm to 100 mm via a 5-turn potentiometer on the top face of the housing. Five full rotations of the adjustment screw span the entire detection range, giving each half-turn of adjustment roughly a 10 mm increment. This resolution makes field calibration straightforward: bring a sample of the target object to the desired detection distance, rotate the potentiometer until the orange output LED activates, and the sensor is set.

The green stability LED confirms that the sensor is operating within its reliable detection margin — not just triggering, but doing so with enough signal margin to remain stable against minor variations in target surface, angle, or ambient light. If the green LED is unlit while the orange output LED is active, the sensor is triggering near its edge of range and may need adjustment or repositioning.

This dual-LED feedback eliminates the guesswork in sensor setup and is especially valuable during initial machine commissioning when the correct mounting distance may not yet be known precisely.

NPN Output: Integration with Sink-Input Control Systems

The WT150-N460's NPN open-collector output is the standard interface for PLCs and controllers using sink-type (NPN) discrete inputs — the dominant convention in Japanese and Asian machine-building practice, and commonly used alongside PNP in European and North American systems.

When the sensor output activates (object detected in light-switching mode, or object absent in dark-switching mode), the NPN transistor pulls the output line toward the supply negative (0V). The PLC input sees this as a low-voltage signal, which it interprets as logic active. The switching mode — light-on or dark-on — is selectable by connecting pin 2 (the L/D control cable) to either the positive supply (L mode: output activates when the beam hits the target) or leaving it open/connected to negative (D mode: output activates when the beam is interrupted).

Maximum output current is 100 mA — well above the typical 5–15 mA draw of standard PLC discrete input cards, leaving ample margin for reliable switching without risk of output overload under normal conditions.

IP67 Sealing in a 7-Gram Housing

IP67 certification means the sensor withstands complete temporary immersion in water to 1 metre depth for up to 30 minutes, in addition to full dust ingress protection. In a 7-gram, 10 × 28 × 18 mm housing, this is a notable engineering achievement. The seal is provided by the M8 connector interface and the precision-moulded ABS housing body, with the PC optics cover integrated into the front face.

For washdown environments in food processing, beverage filling, and pharmaceutical packaging — where regular high-pressure cleaning is part of daily operation — IP67 means the sensor survives the cleaning cycle without requiring protective covers or special handling. In metalworking environments with coolant mist or cutting fluid spray, the same rating keeps the optics and electronics dry without special installation precautions.

The ABS housing and PC optics resist most common industrial solvents and cleaning agents under normal contact conditions. For environments involving prolonged chemical immersion or aggressive solvent exposure, SICK offers chemical-resistant cable and connector options as accessories.

1,000 Hz Switching Frequency for High-Speed Detection

The WT150-N460 switches at up to 1,000 Hz — one thousand switching events per second — with a response time of 0.5 ms or less. At a typical conveyor speed of 1 m/s, a 1,000 Hz switching frequency means the sensor can theoretically distinguish objects spaced as close as 1 mm apart. In practice, reliable object discrimination depends on the size of the objects relative to the beam diameter, but the fundamental speed capability is there for demanding high-throughput applications.

This combination of fast response and background suppression makes the WT150-N460 well-suited for:

High-speed part counting on assembly lines and conveyor sorters
Label detection on packaging lines at elevated production rates
Edge detection on printed materials and film webs
Position detection for pick-and-place robot arms cycling at high frequency
Presence/absence verification in automatic assembly systems where cycle times are measured in fractions of a second

Wiring: M8 4-Pin Connector, Standard SICK Pinout

Pin	Wire Colour	Function
1	Brown (BN)	+V supply (L+)
2	White (WH)	L/D mode select
3	Blue (BU)	GND (M, 0V)
4	Black (BK)	NPN output (Q)

Pin 2 sets the switching mode: connecting to +V selects Light mode (output activates on object detection); connecting to GND or leaving open selects Dark mode (output activates when no object is detected). No separate teach button or parameter setting is required — the mode selection is a simple wiring choice.

Compatible cable and connector accessories include the STE-0804-G (M8 male, 4-pin, screw terminal, straight) for direct termination in a terminal box, and the YF8U14-050VA3XLEAX 5-metre sensor/actuator cable for standard installation runs.

Frequently Asked Questions

Q: What is the difference between the WT150-N460 and WT150-P460?

A: The two models are identical in all mechanical and optical specifications — same housing, same sensing range, same connection, same adjustment. The only difference is the switching output type. The WT150-N460 has an NPN (current-sinking) output, used with NPN/sink-input PLC cards. The WT150-P460 has a PNP (current-sourcing) output, used with PNP/source-input PLC cards. Both support light/dark switching mode selection via the L/D control cable.

Q: What does background suppression mean, and why does it matter?

A: Background suppression (BGS) means the sensor uses triangulation to detect only objects within the set sensing range, and ignores reflections from surfaces beyond that range — regardless of how bright or reflective the background is. A standard diffuse sensor can false-trigger on a reflective background behind a dark target. BGS eliminates this by making detection distance-selective rather than intensity-selective. The result is reliable detection across a wide range of target and background material combinations.

Q: What is the sensing range, and is it adjustable?

A: The maximum sensing range is 2–100 mm (measured on a standard white target at 90% remission). The detection point within that range is set with the 5-turn potentiometer on the sensor body. Rotating clockwise increases the detection distance; counterclockwise decreases it. Five full turns span the full 2–100 mm range. The green stability LED confirms when the sensor is operating with adequate signal margin at the set range.

Q: How do I select light-on vs. dark-on (Light/Dark mode)?

A: Connect pin 2 (white wire, L/D) to the positive supply (+V) for Light mode — output activates when an object is detected within range. Connect pin 2 to GND or leave it open for Dark mode — output activates when no object is detected. No software or teach procedure is required; it is a direct wiring selection.

Q: Is this sensor compatible with 24V DC PLC systems?

A: Yes. The WT150-N460 operates across a supply range of 10–30V DC, covering both 12V and 24V DC systems. The NPN output switches up to 100 mA, which is compatible with all standard PLC discrete input modules.

Q: Can the sensor be used in washdown or food-processing environments?

A: The IP67 rating means the sensor withstands dust ingress and temporary water immersion to 1 metre depth. It is suitable for regular water-based washdown environments. For applications involving aggressive cleaning chemicals or solvents, check chemical compatibility of the ABS housing material and use appropriate cable and connector accessories for chemical-resistant installations.

Q: What mounting hardware is included with the sensor?

A: Every WT150-N460 is supplied with the BEF-W150-A mounting bracket. This bracket allows the sensor to be mounted via the 3.1 mm mounting holes on the sensor body, providing a secure, adjustable installation without requiring a separate bracket purchase for standard setups.

Q: What does "New Sealed" mean for this listing?

A: The sensor is factory-new, genuine SICK manufacture, in original sealed packaging, unused and uncalibrated. Part number 6011047. It has never been installed, powered, or exposed to process conditions. This is not a repaired, refurbished, or repackaged unit.

WT150-N460 New Sealed WT150N460 Sick Photoelectric Sensor Switch