Premises Security > Access Control

Every business should have a reliable door-locking system at the front lines of its defense. One fail-safe way to get one is to use electromagnetic locks.

These types of locks include an electromagnet that you mount on the door frame and a metal strike plate that you attach to the door itself. Adapter and angle brackets can be added to accommodate different swinging patterns. When a door is closed, magnetic force holds the door in place. Shutting off power to the magnet, such as by a signal sent from a card reader or a central access control system, enables the door to be opened.

Most quality magnetic locks offer a minimum of 300 pounds of holding force. To stop the most determined intruders, you can find maglocks that offer up to 1500 pounds or more of holding force.

The type of magnetic system you choose depends on the door’s location, whether it’s a gate on an outside fence, a door to an ordinary interior office, or an access point to an industrial research lab. Magnetic locks installed on doors are usually used with traditional door-latch hardware, and they strongly suit entryways that see a lot of traffic. Plus magnetic systems operate electrically, so they have a long life.

You must also consider the level of safety so employees or tenants can make a quick exit in the event of a fire while first responders can enter without obstruction. All magnetic locks have an egress mechanism to enable a door to unlock in such emergencies. Because they’re electronic devices, they unlock automatically if there’s a power outage. Some can also be unlocked upon command from a fire panel.

Simple locks for ordinary doors and gates
For locking low-level security access points, such as gates to fenced-in areas of a corporate campus or parking lots, you may only need small magnetic locks that can provide a surprising amount of holding force when affixed to a door frame or gate post. These locks may involve some level of remote operation with a central or distributed access control system.

These compact-style magnetic locks can also be used in interior applications. Their slim size makes them the ideal type of lock for cabinet doors, drawers, file cabinets, and safe-deposit boxes. And as long as they have a well-confined magnetic field, they can be also be used in electronically noisy areas, such as computer rooms or factory floors. Many small magnetic locks even include surge suppressors to prevent power anomalies from bringing down their connected access control systems.

Locks specifically designed for exit door control
If you need a lock for security that complies with National Fire Protection Association (NFPA) Life Safety Code provisions, then you’ll likely need a lock that’s specifically designed for exit door control systems. These units are ideal for use with fire- and hazard-detection systems to provide unobstructed egress.

Low-security exit door magnetic locks can be used with lightweight interior doors and typically have a holding force that’s sufficient for many supervised or interior control installations. These locks can be controlled and monitored individually, sequentially, or simultaneously from one or several locations. They are ideal for perimeter protection systems with automatic swinging and sliding door systems as well as intrusion alarm systems.

Locks for harsh, noisy environments
For doors or gates within an industrial environment or anywhere there’s an extraordinary amount of electromagnetic noise, choose magnetic locks specifically designed for these applications. Industrial magnetic locks draw their strength from a housing that seals their internal electronics from interference. They may also feature a metal-plated housing armature and face that resist rust and corrosion.

Helpful magnetic door accessories
Many magnetic lock technologies address some common door problems. Mortise lock-and pull-systems, for instance, address door “racking“ that can occur with header-mounted magnetic locks. They work by putting the magnet directly opposite the direction of the pull. Some lock-and-pull door systems even have magnetic bond sensors that detect a misaligned mating of the armature or whether there isn’t enough power to maintain the lock’s rated holding force.

To override a magnetic lock that’s attached to an electrically operated entrance control system or similar equipment, you can add key-operated mortise cylinder switches. These switches enable authorized users to bypass or shunt door alarms and delayed-release exit control systems with a key. This way, you can restrict door access to key-carrying personnel, such as guards, during certain times of the day.

For applications where you want to provide easy exit, add exit-release push buttons to your magnetic doors. These conspicuous (often red-colored or -lettered, and sometimes illuminated) palm button assemblies provide easy door release.

You can also set up some button- or plate-operated systems to sound an alarm and automatically lock the door once it’s opened. These doors can only be unlocked with a key.

Other button- or plate-controlled exit systems include a console-style key switch for day/night control of automatic doors. You can mount this console under a desk or counter for use by personnel with a key at certain times of the day.

When you have something valuable—your network servers, for instance—you want to limit access. But traditional mechanical locks and keys have severe limitations when you want to limit or control access to a large space shared by many users. It’s a matter of degree: A locked server cabinet with two keys in the hands of two IT members is not a problem; a locked server room with many keys in the hands of a large IT staff is a problem. When many people have keys, problems arise because keys can be lost, stolen, or duplicated. It becomes easy to lose track of who has keys and, if there’s a security problem, you have no idea who had access, and you may have to re-key the locks and replace all the keys.

Electronic access control solves the problems associated with traditional mechanical keys through the use of electronic locks in which each user has a unique electronic key. Electronic access enables you to control who is allowed into your building, who can get into each area within your building, and which times access is allowed. It even enables you to track when and where each user enters.

How access control works.
For electronic access control, an electronic credential is provided to each user. This can be a magnetic card, a personal identification number (PIN) to enter onto a keypad, or even a biometric scan. The user presents this credential to a reader to be granted entry. However, the reader doesn’t make the decision about whether to grant entry; this decision is made by a device called a door controller. A door controller contains the programming to manage all aspects of an entryway and may manage as many as eight readers. It receives information from the reader, makes the decision to open the entryway, and activates the lock relay controlling the entryway. It may also record all entries in real time, which can later be downloaded to a PC for archiving and reporting. Door controllers are frequently linked to a central system so all entryways can be monitored from one location.

Electronic access control primarily uses one of three different kinds of electronic credentials: proximity (close-range or long-range), keypad, or biometric.

The close-range proximity electronic credential is an electronically encoded card or tag that is swiped through a card reader or simply presented near a reader to gain entry. Close proximity credentials are by far the most popular kind used for access control but can be vulnerable to illegal entry by a person who’s found or stolen a card.

Long-range proximity electronic credentials are also available. These systems usually have ranges of a few feet rather than the mere inches of a close-range system. Although they can be valuable for parking areas or handicapped entrances, these long-range systems tend to have the problem of being inadvertantly tripped by a passerby with a credential.

A keypad credential requires a user to type a PIN into a keypad before granting access. These systems are generally regarded as less secure because users may “lend” their codes to another person but cannot prevent further use unless the code is changed. It can also be relatively easy to learn a code through watching.

The most sophisticated type of credential is the biometric in which a user presents a body part to be scanned before being granted entry. The most common kinds of biometrics in use today are iris scans and thumbprint scans, although some systems also use other distinct identifying characteristics such as facial appearance, hand geometry, handwriting, retinal pattern, vein pattern, or voice.

There was a time when biometrics had a reputation for being slow and unreliable. However, the technology has improved dramatically in recent years and—unlike proximity credentials and PINs—biometrics are almost impossible to borrow or counterfeit, making this one of today’s most reliable choices.

For areas where security requirements are very stringent, it’s not uncommon to require two different electronic credentials (for instance, a magnetic swipe card along with a PIN).

The advantage of tracking.
A major advantage of electronic access control is the authority it gives you. Not only does it enable you to decide exactly who is allowed to go where and when, but it also documents and reports access activity. If you have a security incident, you can quickly learn who had access to critical areas before and after the incident. Electronic access control is a perfect complement to video surveillance and alarm systems in a comprehensive security plan.

Who uses electronic access control?
• Secure server rooms use it to prevent sabotage or vandalism.
• Hotels use it by providing electronic room keys that can also open doors to pool and spa areas.
• Hospitals use it to keep unauthorized personnel from seeing private records and to secure sensitive areas such as pharmacies and surgical floors.
• Day care centers use it to ensure that no strangers have access to their charges.
• Parking areas use it to prevent car theft and carjackings.