The beam solution is the “original” method of counting traffic. Even today, beam solutions produce a reliable number and can obtain high accuracy, but their effectiveness is highly dependent on the following:
Firstly, for a beam system to work, it needs a clear line of sight between its two components. These are usually called a receiver and a transmitter.They are installed on each side of the door and this is where point #1 and #2 are important.
Regarding point #1, beams can have a high range (15 to 25 feet is typical and up to 100 feet is possible). If your entrance is extremely broad and/or it possesses displays, such as a table or a rack with items, it could cause the beam to get blocked by the display and render it ineffective. If displays encourage people to stop where the beam is, the person can block it, and sometimes they can obstruct it long enough to avoid the counting of other people entering the location.
Now to point #2- the entrance design. Particularly in malls, entrances have evolved tremendously in the last ten years. Frameless design with glass doors is growing in popularity, which makes the installation of the beam almost impossible because of the effect it would have on the store layout. Also,the lack ofa door frame to mount the beam and thefact that the doors now create a backswing that blocks the beam when they are opened make it close to impossible to consider a beam based traffic counting system Regarding point #3, the beam is a passive and simple system. This means that if your traffic flow is high, and two or more people are entering your store side by side at the same time, the beam will only count this as one person.