When most people picture a security system, they imagine motion sensors detecting a burglar walking through a living room. While motion detection is crucial, it has one flaw: the intruder is already inside.
A truly robust security strategy starts at the perimeter. In Sri Lanka, statistics indicate that the vast majority of unauthorized entries occur through a ground-floor door or window. To secure your home or business effectively, you need to stop the threat before it crosses the threshold.
This is where the Ajax DoorProtect Jeweller comes in. It is not just a sensor; it is the foundation of a secure perimeter, engineered to provide instant notification the moment a door, window, or gate is breached.
The Foundation of a Secure Perimeter
The philosophy behind the DoorProtect is simple: Prevention is better than cure. By securing every entry point, you create a “shield” around your property.
This allows for “Night Mode” protection. You can arm the perimeter (doors and windows) while keeping the interior motion sensors disarmed. This means you and your family can move freely inside the house, watch TV, or go to the kitchen for a midnight snack, while sleeping soundly knowing that the outer shell of your home is fully armed and watching.
Advanced Technology: The British-Made Heart
Reliability in a door sensor comes down to one component: the reed switch. Many budget alarm systems use cheap, mass-produced switches that often stick or fail after a few months of humid weather—a common issue in Colombo.
The Ajax DoorProtect is in a different league. At its heart lies a high-end reed relay manufactured in the UK.
This component is built to withstand extreme stress and is rated for over 2 million openings. Whether you are securing a rarely used back door or a busy retail shop entrance that opens hundreds of times a day, the DoorProtect is built to last for decades, not months.
How It Works: Simplicity Meets Science
The device consists of two compact units: the detector (which houses the electronics and reed switch) and a magnet.
- The Setup: The detector is mounted on the door frame, and the magnet is mounted on the moving part of the door or window.
- The Trigger: When the door is closed, the magnet keeps the circuit complete. The moment the door opens, the magnetic field is broken.
- The Alert: In less than 0.15 seconds, the sensor sends an encrypted alarm signal to your Ajax Hub via the Jeweller radio protocol, which then instantly notifies your smartphone and the SecureLink monitoring center.
Technical Deep Dive: Why It Wins
1. Impressive Wireless Range One of the biggest challenges in large Sri Lankan homes is concrete walls blocking Wi-Fi signals. The DoorProtect doesn’t use Wi-Fi. It uses Ajax’s proprietary Jeweller protocol, which can maintain a stable connection with the Hub at a distance of up to 1,200 meters (in open space). This incredible range means you can secure a detached garage, a garden gate, or a security hut without needing complex wiring or signal repeaters.
2. Dual Magnet System for Flexible Installation Not all doors are flush with the frame. Modern aluminum sliding windows often have uneven gaps. To solve this, SecureLink provides two magnets with every unit:
- Large Magnet: Works at a distance of up to 2 cm (ideal for doors).
- Small Magnet: Works at a distance of up to 1 cm (perfect for tight window frames). This ensures that no matter the architectural style of your home, the sensor fits perfectly.
3. 7-Year Battery Life Maintenance is a hassle. The DoorProtect is designed to be an “install and forget” solution. Powered by a single pre-installed CR123A battery, it operates efficiently for up to 7 years. You won’t be climbing ladders to change batteries every six months.
4. Anti-Sabotage & Encryption Security devices must be secure themselves. All data transmitted is protected by block encryption with a floating key. Furthermore, the device features a Tamper Button. If a burglar tries to pry the sensor off the door frame, the button is released, and the alarm triggers immediately—even if the system was disarmed.
Real-World Use Cases in Sri Lanka
The “Chime” Feature for Retail For shop owners, the DoorProtect doubles as a customer greeter. When the security system is disarmed during business hours, the sensor can be programmed to emit a pleasant “Chime” sound from the Ajax Siren whenever the door opens. This alerts staff that a customer has walked in, without triggering a full alarm.
Valuables Protection Think beyond the front door. The compact size of the DoorProtect makes it ideal for internal security:
- Gun Cabinets: Get alerted instantly if your firearm storage is accessed.
- Safes: Know exactly when your safe is opened.
- Medicine Cabinets: Keep dangerous medication away from children.
Expert Advice from SecureLink
At SecureLink, we design systems that close every loophole. We highly recommend installing DoorProtect sensors on:
- All ground-floor windows: These are the most common entry points for burglars.
- Balcony doors: Especially those accessible via a pipe, tree, or nearby wall.
- Roof access hatches: Often overlooked, but a prime entry point for determined intruders.
Don’t leave your perimeter to chance. Secure the shell of your property and stop the intrusion before it happens.
