WTB250-2P2451 Sick

What type of sensor is this device?

It is a compact photoelectric proximity sensor designed for direct object detection. It uses background suppression to distinguish a target from surfaces located behind it.

What is the adjustable sensing range?

The sensing range can be adjusted from 200 mm to 1,000 mm. The stated range is based on an object with 90% remission relative to standard white according to DIN 5033.

What type of light source does the sensor use?

The sensor uses a visible red LED, which helps with optical alignment during installation. The light spot is approximately 35 mm in diameter at a distance of 1,000 mm.

How is the sensing distance adjusted?

The switching distance is set using a two-turn potentiometer with a position indicator. This allows the detection threshold to be adapted to the target and background.

What electrical supply does the sensor require?

The WTB250-2P2451 operates from a 10 to 30 V DC supply. Its current consumption is approximately 35 mA without a connected load.

What type of switching output is provided?

The device has a PNP switching output rated for an output current of up to 100 mA. It can operate in either light-on or dark-on mode.

How is light-on or dark-on operation selected?

The switching mode is selected through the dedicated L/D control connection. This enables the output behaviour to be configured for the application.

What connector does the sensor use?

Electrical connection is made through a four-pin M12 male connector. The connector position can be rotated through 90 degrees to suit different mounting arrangements.

What is the M12 connector pin assignment?

Pin 1, brown, is L+; pin 2, white, is the L/D control input; pin 3, blue, is M; and pin 4, black, is the switching output Q.

How quickly does the sensor respond?

The response time is no more than 3 ms with a resistive load. The maximum switching frequency is 160 Hz at a light-to-dark ratio of 1:1.

What environmental protection does the housing provide?

The housing is rated IP67, providing protection against dust ingress and temporary immersion under the conditions defined by the rating.

What are the permitted operating and storage temperatures?

The operating temperature range is -25°C to +55°C. The permitted storage temperature range is -40°C to +70°C.

What are the sensor's dimensions and weight?

The rectangular housing measures 20 mm wide, 65 mm high and 43.9 mm deep. The device weighs approximately 40 g.

What materials are used in its construction?

The housing is manufactured from ABS plastic, while the optical components use PMMA plastic. This combination provides a compact and lightweight industrial sensor body.

Is a reflector required for operation?

No. This is a direct-detection photoelectric proximity sensor, so it detects light reflected from the target itself rather than relying on a separate reflector or receiver.

What does background suppression do?

Background suppression helps the sensor respond to an object within the configured sensing range while reducing unwanted switching caused by surfaces positioned farther away.

What indicators are fitted to the sensor?

A green LED indicates signal stability, while a yellow LED indicates the light reception or switching status. A separate position indication assists with sensitivity adjustment.

What mounting accessory is supplied with the device?

The BEF-W250 mounting bracket is included. The sensor body also has 4.2 mm through-holes designed for M4 mounting hardware.

Does the sensor include electrical protection features?

Yes. Its connections, inputs and outputs include reverse-polarity protection, interference-pulse suppression, and output protection against overcurrent and short circuits.

Which electromagnetic compatibility standard does the device meet?

The sensor is specified for electromagnetic compatibility in accordance with EN 60947-5-2, a standard associated with industrial control-circuit devices and proximity sensors.