Controlling Access In Commercial Buildings
Since 9/11, commercial buildings, institutions and government agencies have been grappling to find cost-effective and aesthetically pleasing ways to control access to their buildings. For most small buildings, it's not a problem. Small buildings can effectively handle the problem by placing card readers on exterior doors. However, with large, busy buildings, the same approach is impractical. Piggybacking (holding the door open for the person behind you) is the major security breakdown problem in high traffic areas such as the main entrance.

The Past Problems
In the past, there have been two ways to effectively manage access in high traffic The first is manual verification. With manual verification, all persons requesting entry to the building must show an authorized badge to a guard before entering. Unfortunately, this approach is costly and provides a very low level of security. The use of guards is just plain expensive. More important, guards can't know for certain whether badges are fake (which is not difficult to do these days) or whether familiar faces are still employed with the company. The second way to manage access into a busy building involves the use of unattractive mechanical turnstiles in the lobby. Most building owners cringe at the thought of using them because they create a “prison like” atmosphere in many lobbies.

The Solution
One practical solution to providing secure high traffic access control in the lobby of a busy building is to use Optical Turnstiles. An Optical Turnstile system is a set of parallel pedestals that form lanes they look like mechanical turnstiles without the barrier Each pedestal is equipped with photo- electric beams and a logic board. Typically, Optical Turnstiles are located in a pivotal mainly location. To gain access to the interior of the building, an authorized person uses their access card at the Optical  lane. Using a valid card temporarily shunts out the turnstile's photo- electric beam, allowing the cardholder to pass without creating an alarm. Attempting to pass through a lane without a valid access card activates a local and remote alarm, alerting security. Some of the newer optical turnstiles also include a waist high Plexiglass or glass barrier to prevent entry without the use of a valid card. Like earlier models, these turnstiles use photoelectric beams and logic boards to prevent piggy-backing as well as shunt out alarms.

Optical Turnstiles are becoming more common fixture in lobbies for several reasons. First, they can be covered with any type of finish (from stainless steel to Corian), complementing lobby decor. Second, They can securely handle heavy traffic -  a typical Optical Turrnstile lane can process 1,200 to 1,800 people per hour. Third, they help limit your liability by allowing you to screen for authorized personnel only This means persons without a valid card cannot access your facility without setting off an alarm and drawing attention. Given current legal trends, more companies will be using this approach to reduce their liability exposure. Finally Optical Turnstiles provide superior visitor management, forcing every visitor to register with your security or reception desk. Breaching building security through “piggybacking" becomes almost impossible.

Three Rules to Follow
When designing your system, the length of the turnstile pedestals should be four to six feet (anything less than four feet can increase the incidence of false alarms). Second, design your system with enough lanes to handle your worst case scenario—rush hour Finally use off-the-shelf designs for the pedestals—architects love to come up with elaborate designs, but they don't have to foot the bill.