Principle of operation
Installation and set up
Principle of operation
Installation and set up
Big magnet — 2 cm
Two-way communication between devices
Radio frequency bands:
866.0 – 866.5 MHz
868.0 – 868.6 MHz
868.7 – 869.2 MHz
905.0 – 926.5 MHz
915.85 – 926.5 MHz
921.0 – 922.0 MHz
(depends on the region of sale)
Self-adjusting RF output power — up to 20 mW
Block encryption based on AES algorithm
Detector polling period — 12−300 s
Learn more about Jeweller
Height: 90 mm
SmartBracket mounting panel
CR123A battery (pre-installed)
Wireless opening sensor Ajax DoorProtect
Reed switches or sensors for opening doors and windows are used to protect the premises from intrusion. Such sensors determine the opening of doors, hatches, windows and other elements.
A reed switch is a sealed switch that operates based on ferromagnetic spring contacts. The principle of operation of the reed switch is as follows:
- Two plates of nickel and steel are placed in a sealed glass flask.
- A magnetic field is created in the flask, which causes the plates’ interaction and the sensor’s operation.
How to choose a door open sensor for alarm
Before choosing an opening sensor, users need to familiarize themselves with its types and operating parameters.
Opening sensors by installation method
Door opening sensors can be mortised or overhead. Installing a mortise reed switch requires special tools and takes time. A sensor with this type of installation is almost invisible in the interior. Overhead reed switches are attached using self-tapping screws or double-sided tape and are easy to install. Opening detectors of this type are exposed to external influences and are noticeable in the interior; this is a disadvantage for security devices.
Opening sensors by type of mounting surface
Window or door opening detectors are installed on plastic, wood or metal. A metal surface reacts to a magnet, like a reed switch, so for metal objects — doors, gates, it is important to choose the appropriate detectors.
Metal heats up and cools down more than plastic or wood, so an improperly selected reed switch may stop working due to the temperature.
Each reed switch has a minimum and maximum operating temperature limit for uninterrupted operation. It must be taken into account before installing the opening sensor.
By response time
The sensors for opening doors and windows contain the response speed of the device. And the likelihood of catching an intruder is higher if the alarm goes off immediately.
By connection type
Window and door opening sensors for alarms can be wired or wireless. Wired devices are connected to the security system’s control panel or GSM alarm system using two cables. Wireless opening detectors report tampering via radio connection and do not require wires.
By place of installation
There are opening sensors for indoor installation and outdoor. Reed switches in a metal case are suitable for outdoor installation on gates. They are protected from the external environment. When choosing a door sensor for an indoor facility, its temperature range must be considered. For example, the window opening sensors are installed on a south-facing window. Users need to consider that in summer, the frame can heat up to 50 °C or more. This may affect the correct operation of the window opening sensor for the alarm.
Signal transmission radius
The signal transmission radius from the opening sensor for signalling to the security unit can be 80 m to 500 m.
Limit number of operations
It depends on the frequency of opening the window or door installed on the opening sensor. The more actively the detector is used, the higher the indicator.
When choosing an opening sensor for signalling, it is necessary to consider the distance between the surfaces on which it will be used, that is, between the contact and driving parts of the reed switch. If the actual distance is higher than in the technical characteristics of the opening detector, then the reed switch will not work.
Conditions for triggering the alarm mode
The distance between the installation location of the opening sensor for signalling and possible false alarm triggers must be taken into account. If the “margin” of the distance is small and the opening detector is installed on the gate, vibration from a passing car will probably trigger a false alarm.
The sensitivity of the opening sensor must correspond to the object on which the installation takes place.
Opening sensor body colour
It is important to choose door and window opening sensors in the colour of the surface on which the device is installed. Thus, the probability that the opening detector will be disabled will decrease, the reed switch will become less visible to an attacker.
Caring for opening sensors
Alarm door detectors do not require special care. They are durable, and the number of valid operations can exceed a million. Sensors that operate on battery power require battery replacement every few years.
Wireless sensor for opening windows and doors Ajax DoorProtect
The indoor unit opening sensor detects intrusion and reports opening a door or window. They are mounted on all kinds and types of objects.
The Ajax DoorProtect wireless opening sensor protects private spaces, public areas, industrial premises, etc.
The principle of operation of the Ajax DoorProtect wireless opening sensor
The Ajax DoorProtect alarm detector for opening doors and windows is designed to detect unauthorized openings when the premises are armed. A block triggers the opening sensor with a reed switch and a magnet.
The principle of operation of a wireless opening detector is based on the properties of a reed switch. This part becomes a signal conductor under the influence of a magnetic field.
The wireless sensor comes with two magnets: large and small for installation up to 2 cm and 1 cm, respectively. In a state of calm, the magnet and the block with the reed switch are closed. When the door on which the detector is located is opened, the magnet moves away from the reed switch, the contacts open, and the reed switch interrupts the current supply. When the door closes, the magnet approaches the reed switch, the contacts close, and the reed switch conducts. In any case, the wireless opening detector is triggered and immediately sends an alarm signal to the alarm control panel. Hub, in turn, informs users about the incident and launches automated actions, depending on the settings.
An English reed switch is installed in the opening sensor for the Ajax DoorProtect alarm. It does not stick and is designed for more than a million operations.
Features of Ajax DoorProtect wireless opening sensor
The Ajax DoorProtect wireless opening sensor works based on two-way radio communication, device forgery protection and information encryption. Also, the DoorProtect opening detector has a communication system that allows it to work within several floors of a building or at a distance of up to 2000 m to the central alarm panel, provided there are no obstacles.
The Ajax DoorProtect opening sensor protects even windows that are open for ventilation. The accelerometer will detect shock, tilt or vibration and alarm the control panel.
Installation and assembly of the Ajax DoorProtect opening detector
The connection and configuration of the wireless opening sensor take place in the Ajax mobile application. The opening detector is mounted on the SmartBracket mount without disassembling the case. The battery is pre-installed and lasts up to 5 years without replacement.