Electronic door counters are just a subset of what's also known as electronic access control systems. These systems detect and measure people entering a building or home, as well as the amount of money they spend while in the home or business. But door counters also detect and count how often a person opens a door. Door counters usually only use the same basic magnetic door sensors found in alarm systems for doors and windows.
A lot of people think that there are only two different kinds of electronic door sensors - magnetic sensor-based ones and those that use infrared heat detection technology. However, the truth is that all of these door sensors use the same principles, which can be classified into six main categories. The six main categories are:
The first type of electronic door counter is the magnetic door counter. This sensor uses a combination of two different kinds of magnetic sensor elements. One uses a magnetic field created by an object moving against the magnet in the opposite end of the bar; the other uses an infrared light source that passes through a door, detecting the light as it passes through the door and emitting a signal when the light is detected. Both types of magnetic elements create an electromagnetic field that can be detected using a transducer.
The second type of door counter is the infrared-based door counter. These use an infrared light source similar to what's used for video surveillance. These devices detect the presence of people or animals outside the property by detecting the heat given off by their bodies. Both types of electronic door counter operate by detecting an infrared signal given off by an animal or humans entering or leaving a room.
The third kind of electronic door counter found in hospitals and medical clinics is called Patient Positioning System sensors. These are installed at various entrance ways to the patient care areas. In the case of a medical facility, these devices are placed at the entry doors to the operating rooms. They detect the movements of people going into or out of the area and trigger the alarm. When the alarm is tripped, the control panel of the device triggers an audible warning.
It's also possible for medical facilities to install emergency exit signs as part of their emergency response system. The signs allow people in the building to get out safely after a medical procedure has been completed.
Before installing any type of emergency exit sign, a physician must evaluate the type of person that may be inside the building and make any necessary adjustments to the emergency system. In the case of a medical facility, the electronic door counter devices are part of the emergency system used to monitor the surgical site and stop any unwanted patients from getting inside the surgical site.