Reed Switch / Magnetic Contact SATEL B-2S-BR cylindrical door/window sensor, tamper-resistant, surface mount

The SATEL B-2S-BR cylindrical door/window sensor is a reed switch designed for monitoring the open or closed state of doors and windows in alarm systems. The sensor consists of two cylindrical parts — a magnet and a contact — intended for surface mounting on frames and sashes to achieve a discreet, low-profile installation. It provides a normally closed contact suitable for control panels that require this wiring configuration and includes tamper-resistant features to detect attempts at unauthorized removal.

Advantages

The cylindrical design allows unobtrusive placement on a variety of door and window profiles while maintaining reliable magnetic contact operation. Surface-mount construction simplifies installation without recessing, and the two-part format provides flexibility in positioning the magnet relative to the sensor. Tamper protection increases system security by signalling when the sensor housing is opened or removed. The device operates as a basic open/close detector compatible with standard alarm control panels expecting a normally closed circuit.

Suitable for

• Monitoring residential and commercial doors for intrusion detection
• Monitoring window sashes and frames where discreet installation is desired
• Use with alarm control panels that accept normally closed contacts
• Applications requiring surface-mounted magnetic contacts without flush mounting

Key specifications

• Form factor: cylindrical two-part sensor (magnet and contact)
• Mounting: surface mount for frames and sashes
• Contact type: normally closed magnetic contact
• Tamper detection: built-in tamper contact to signal housing removal
• Construction: compact, low-profile body for discreet installation

How to use

Mount the sensor body on the fixed frame and the magnet on the moving sash so that when the door or window is closed the two parts align within the recommended gap for reliable operation. Connect the sensor leads to the alarm control panel input configured for a normally closed contact, and connect the tamper output to the corresponding tamper input if available on the panel. Verify correct alignment and wiring by observing the panel's status or using a multimeter to confirm the closed/open state during normal and opened positions.

Usage recommendations

Position the magnet and sensor with minimal gap and secure attachments using appropriate screws or adhesive for the surface material. Test the tamper feature after installation to ensure the housing removal triggers the tamper input. Avoid placing the magnet near other strong magnetic sources or metal objects that could interfere with operation; if the door or window has thick frames or non-standard profiles, check alignment and spacing before final fixing.