Magnetic door sensor BLOW 4916# HO-03 brown — reed switch contact for door/window security

The BLOW magnetic door sensor 4916# HO-03 in brown is a compact reed-switch contact designed to monitor the open/closed status of doors and windows. The sensor comprises a switch body and a separate magnet; when the magnet moves away from the switch, the reed contact changes state to signal an opening. It is intended for surface mounting and integrates with alarm panels, home security systems and access control units where a low-profile, brown finish is required.

Advantages

This magnetic sensor offers a simple, reliable contact mechanism based on a reed switch, providing consistent detection of door and window openings. Its compact dimensions and surface-mount design make installation straightforward on frames and sashes without extensive modification. The brown casing provides discreet visual integration with wooden doors and dark-coloured frames. The sensor operates without batteries or separate power supply for the contact itself, reducing maintenance needs when used as a passive zone input to alarm or access control systems.

Suitable for

• Basic intrusion detection on doors and windows
• Status monitoring for home security systems and alarm panels
• Integration with access control devices to detect door/window positions
• Retrofit installations on wooden doors, frames and dark-coloured joinery

Key specifications

• Sensor type: reed contact (magnetic switch)
• Mounting: surface mount for door frames and window sashes
• Finish: brown casing suitable for dark-coloured joinery
• Components: separate switch body and matching magnet
• Signal: normally closed / normally open contact state (changes when magnet is separated)
• Compatibility: intended for wired connection to alarm panels and access control inputs
• Operating principle: passive magnetic actuation, no internal power for the contact

How to use

Position the switch body on the stationary part of the door or window frame and the magnet on the moving sash so that they align when the door or window is closed. Fix both parts using screws or adhesive as appropriate for the mounting surface, ensuring the specified gap for reliable operation is maintained. Connect the sensor leads to the alarm panel or access control input following the panel manufacturer’s wiring diagram, observing correct tamper and zone configurations if required. Test the contact by opening and closing the door or window to confirm that the system registers the change of state.

Usage recommendations

For reliable long-term operation, install the sensor on clean, dry surfaces and avoid placing the magnet beyond the recommended gap. Use screws for permanent mounting on wooden frames; use suitable adhesives only when mechanical fixing is not possible. Verify compatibility with the control panel’s input type and perform periodic functional tests as part of routine system maintenance.