SICK WTB12-3P2461S58 Proximity Sensor

WTB12-3P2461S58 is a SICK W12 photoelectric proximity sensor with background suppression, ordered under part number 1047850. It switches when a target sits inside its set sensing range and does not react to surfaces behind that range, which is what makes the principle useful on conveyors, pick-up stations and machine frames where the backdrop is a wall, a guard or another product. The data sheet gives a maximum sensing range of 30 mm … 500 mm (sensing range value printed as 50 mm … 500 mm). The switching output is PNP with light/dark switching, the supply is 10 V DC … 30 V DC and the connection is Male connector M12, 4-pin.

How WTB12-3P2461S58 switches on the target and ignores the background

Background suppression is a triangulation method: the receiver sees the returning light spot at a position that depends on object distance, and only spots inside the cut-off set at the adjuster switch the output. Because the decision is geometric rather than energy-based, target colour and gloss matter far less than with a plain diffuse proximity sensor, although very shiny or strongly angled surfaces still deserve a trial on the real part.

Its emitter is a PinPoint LED emitting visible red light with a spot of 50 mm x 5 mm (150 mm). It is adjusted through potentiometer, 5 turns. It responds in ≤ 700 µs.

Technical specifications

Type code WTB12-3P2461S58 and part number 1047850

SICK builds a type code from the family prefix (WTB12 here), housing and option digits and, on some devices, a suffix for a factory-specific variant. The digits alone do not tell you everything, so quote the seven-digit part number 1047850 as the unambiguous key: variants that differ only in connection, output polarity or range each carry their own part number.

Other active types in the same SICK family, each with its own part number:

• WTB12-3P2461S02 (part no. 1055582)
• WTB12-3P2461S01 (part no. 1051967)
• WTB12-3P2441S59 (part no. 1056725)
• WTB12-3P2431S60 (part no. 1052578)
• WTB12-3P2431 (part no. 1041411)

Mounting, wiring and set-up notes for WTB12-3P2461S58

Plan for 10 V DC … 30 V DC at the terminals, IP66; IP67; IP69K enclosure protection and an operating ambient of –40 °C … +60 °C. Current draw is 40 mA. The body measures 15.6 mm x 48.5 mm x 42 mm and weighs 120 g. Make sure the controller input matches the output type; a PNP sensor cannot simply replace an NPN one without changing the input wiring.

Selection checks before replacing or specifying the sensor

When this sensor replaces an existing unit, compare more than the type code. Check that the target distance on the machine falls comfortably inside the sensing range rather than at its edges, that the controller input accepts a PNP signal, and that the M12 connection matches the cable already installed. Look at what sits behind the target: background suppression handles a wall or guard well, but a background that moves into the set range, such as a swinging chute or a product on a parallel lane, will still be detected. For a new application, test the sensor on real parts, including the darkest, the brightest and the most angled ones that will pass, and confirm that the switching point stays stable across all of them.

Alignment and commissioning steps

Fix the sensor so that the line-shaped light spot falls on the part of the target that is always present, and keep the mounting rigid; vibration that moves the sensor relative to the conveyor shifts the switching point. With a typical target in the detection position, turn the potentiometer to find the point at which the output switches, then repeat with the target at the far edge of its expected position and with no target present. Set the final adjustment with margin on both sides so the sensor does not chatter between states. Record the setting and the light/dark mode used, and confirm in the controller that the signal changes state at the expected moment in the machine cycle.

Routine checks

A photoelectric sensor that worked on day one can drift into intermittent faults as the front screen becomes dirty or the mounting loosens. During planned maintenance, clean the front screen with a soft cloth and a cleaning method suitable for PMMA, check that the connector is tight and the cable is not strained, and confirm the switching point with a reference target.

Dust, heat and wash-down in GCC plants

Packaging lines, bottling halls and warehouses in Oman and the wider GCC are often dusty, and some facilities face fine sand carried in through loading doors. Dust on the front screen reduces the light returning to the receiver, so set a cleaning interval that reflects the actual conditions rather than waiting for false trips. Keep the sensor out of direct sunlight where possible, since strong ambient light and solar heating on a metal housing are both avoidable stresses. Compare local conditions at the mounting point with the ambient temperature and enclosure ratings in the data sheet, especially near ovens, shrink tunnels or outdoor loading areas.

Documents and quotation

Download the SICK data sheet for WTB12-3P2461S58 from this page. It is the manufacturer’s PDF for part no. 1047850, unchanged, and it carries the drawings and the full parameter list. Quote the part number in the RFQ form together with the quantity and delivery location, and our team will respond with pricing. Related items are listed under Sensors & Transmitters. Compare the connection, the output and the ratings with your existing installation first; the PDF governs if it differs from this text.