Federal standard

UNCONTROLLED AREA An area in which uncleared personnel are allowed uncontrolled access.

UNCONTROLLED CROSS KEYING A condition in which two or more different keys under different higher level keys operate one cylinder by design; e.g., XAA1 operated by AB, AB1. NOTE: This condition severely limits the security of the cylinder and the maximum expansion of the system, and often leads to key interchange.

UNDERDOME BELL A type of bell in which the activating mechanism is housed beneath the sounding dish.

UNDERSHOOT The voltage which goes below the required voltage when correcting for a surge in the line voltage.

UNDERWRITER'S LABORATORIES, INC. (UL) A nonprofit national testing laboratory that tests and certifies various categories of equipment and electrical apparatus for safety and reliability. U.L. publishes comprehensive standards for wide range of products, including security and fire protection equipment. U.L. standards may also cover installation and maintenance. U.L. certified equipment is required by insuring agencies for many types of installations.

UNIDIRECTIONAL CYLINDER A cylinder whose key can turn in only one direction from the key pull position, often not making a complete rotation.

UNIFORM CRIME REPORTS Compilations of statistics of common crimes, issued annually by the FBI for use by all state and local agencies.

UNINTERRUPTIBLE POWER SOURCE (UPS) A power source that is supported by a backup battery or other power generating source for use in the event of a primary power failure. Once input power to the supply is lost, switch over to the backup source is instantaneous to prevent even a momentary loss of power. Uninterruptible power sources are essential for most security installations. A power failure of extremely short duration could cause a memory loss in a computerized system. Also called an uninterruptible power supply.

UNIT LOCK See Preassembled Lock.

UNIVERSAL ASYNCHRONOUS RECEIVER/TRANSMITTER (UART) A device that interfaces a word parallel controller or data terminal

over two lines to a bit serial communication network.

UNIVERSAL KEYWAY See Composite Keyway.

UPGRADE This is a determination that certain classified information, in the interest of national security, requires a higher degree of protection against unauthorized disclosure than is currently provided, coupled with a changing of the classification designation to reflect such a higher degree. See

UPS See Uninterruptible Power Source.

USER AGENCY The DoD or Federal organization sponsoring a classified contract.

USER IDENTIFICATION NUMBER Number that uniquely identifies a user of a computer system. Used to monitor access and, in some instances, for usage billing.

W

WAFER See Disc Tumbler and Master Pin.

WALK TEST LIGHT A light on motion detectors which comes on when the detector senses motion in the area. It is used while setting the sensitivity of the detector and during routine checking and maintenance.

WALK UNDER The ability to defeat a volumetric or span sensor by physically passing through a blind area directly underneath or just in front of the unit.

WALKTEST A test of a sensor, in which an individual moves within the sensor's anticipated pattern of coverage. A walktest light or output display indicates the limits of the pattern for final adjustment of the desired coverage.

WARD A usually stationary obstruction in a lock or cylinder which prevents the entry and or operation of an incorrect key.

WARD CUT A modification of a key which allows it to bypass a ward.

WARDED LOCK A lock containing internal obstacles which block the entrance or rotation of all but the correct key.

WATCHMAN An individual not necessarily uniformed or armed with a firearm, who provides protection for a plant in the course of performing other duties.

WATCHMAN'S CLOCK A mechanical recording clock carried by a guard during rounds. A specified check points, a key located at the checkpoint is inserted into the clock to document the stop.

WATCHMAN'S REPORTING SYSTEM A supervisory alarm system arranged for the transmission of a patrolling watchman's regularly recurrent report signals from stations along his patrol route to a central supervisory agency.

WATCHTOUR The physical inspection of a facility by a guard. The watchtour usually requires a given number of inspections with check stops at specified points throughout the tour. The check stops along the route must be verified by some documentation method. For this purpose, watchman's clocks and electronic watchtour systems are used. Also called a guard tour.

WATER DETECTOR A device that electronically or mechanically senses the presence of water. It is used to detect leaks, broken pipes, pump failures, and water levels. One type initiates an alarm signal when water allows electrical current to pass between two metal probes. See also Moisture Detector.

WATER FLOW TRANSMITTER A device that transmits a signal indicating that water is flowing through an automatic fire sprinkler system. Incorporates a diaphragm time delay to prevent false alarms caused by minor water surges.

WAVEFORM MONITOR A special oscilloscope that analyzes the waveform of video signals.

WAVELENGTH The distance between successive peaks of the electrical or magnetic fields in an electromagnetic wave.

WET CELL A rechargeable battery that has lead acid or lead calcium grids. This classification of batteries requires a liquid electrolyte that must be maintained within a specified level.

WET GLAZING The sealing of glass or other transparent material in a frame by the use of a glazing compound or sealant.

WHITE LEVEL The limiting of the video picture signal to the maximum level specified for white peaks.

WIDE ANGLE LENS A lens with a short focal length designed to show a wide to extremely wide angle of view. Wide angle lenses can cover large viewing areas, or the entire area of a confined space such as an elevator. Wide angle lenses can provide better depth of field than longer lenses given the same amount of available light.

WIDE GAP CONTACT A special type of door contact designed to work efficiently in applications where there is a greater distance between contact pairs than required of standard door contacts.

WIEGAND EFFECT A unique magnetic phenomena discovered by John R. Wiegand. The effect involves the way magnetic fields in specially prepared wire suddenly and forcibly reverse them selves when exposed to an external magnetic field. The special wire is a magnetically unstable ferromagnetic wire that is formed in permanently tensioned helical twist. The magnetic reversals can be converted into distinct consistent electrical pulses. This effect has been successfully used in access control systems. Wiegand wire cards are relatively expensive to produce but are difficult to duplicate.

WIEGAND WIRE CARD READER A relatively low priced card reader designed for use with Wiegand wire cards. It comprises a magnetic sensing coil that picks up the flux reversals characteristic of a Wiegand wire card and converts them to binary pulses. See also Wiegand Effect.

WIGGLE KEY See Manipulation Key.

WINDOW FOIL Thin metal tape applied to windows and similar breakable surfaces to detect intrusion or damage. The foil conducts a current and serves as an alarm circuit. A break in the foil causes a fault condition.

WINDOW FRAME See Frame.

WINDOW GUARD A strong metal grid‑like assembly which can be installed on a window or other opening; types of window guards include metal bars, metal mesh grilles, and sliding metal gates.

WIPE‑THROUGH CARD READER A card reader in which the information is obtained by passing or "wiping" the card through an open slot in the read head device. Since the card is not inserted in an enclosed cavity, the possibility for jamming is reduced. Wipe‑through card readers were designed for higher throughput and reduced maintenance time.

WIRE GLASS Glass manufactured with a layer of mesh approximately in the center of the sheet.

WIRE WRAP A method of making temporary wire connections without solder. Small gauge solid core electrical wire is stripped near the ends and wrapped tightly around a square or flat metal pin using a special tool.

WIRELESS SECURITY SYSTEM A security system that does not use hardwire to receive alarm data from some or all of the sensors in the system. A radio frequency link is established between the sensor and the central controller. By using a transmitter at the sensor end and a receiver at the central controller, alarm data may be sent just a few feet or several miles depending on the type of rf link used. Control outputs are also possible with some wireless systems.

WIRETAPPING, ACTIVE The attaching of an unauthorized device, such as a computer terminal, to a communications circuit for the purpose of obtaining access to data through the generation of false messages or control signals, or by altering the communication of legitimate users;

WIRETAPPING PASSIVE The monitoring and/or recording of data while the data is being transmitted over a communications link.

X

X Symbol used in hardware schedules to indicate a cross keyed condition for a particular cylinder; e.g., XAA2 X1X (but not AX7).

X‑RAYS Electromagnetic waves with shorter wavelengths than light or ultraviolet rays. They can pass through many materials which are opaque to light rays.

X‑RAY SYSTEM A device or system that inspects the contents of a package or container for concealed explosives or contraband. Applications include airport security, postal inspection, explosives detection, and customs.

XENON A gas used in some modern high intensity lamps and flash tubes.

Y

Y SIGNAL In color television, the signal that contains the fine detail and brightness information. The signal comprises 0.30 parts red, 0.59 parts green, and 0.11 parts blue. The Y signal produces a black and white image on a monochrome video display unit.

ZERO BITTED Of or pertaining to a cylinder which is or is to be combinated to keys cut to the manufacturer's reference number "0" bitting.

ZERO CROSSOVER POINT In ac power circuits, the point at which the positive (or negative) voltage swing drops to zero before rising to its reversed value.

ZINC CHLORIDE BATTERY A heavy duty battery for use in electronics. Similar to a carbon zinc battery, except that ammonium chloride is not used, and a high grade of manganese dioxide is utilized. These batteries have a longer life than standard carbon zinc batteries.

ZONE 1. A specified area of protection. A zone often means a space having one or more sensors. 2. A single secure point, as an input to an alarm device or as displayed on an annunciator. It is usually assigned a unique number or identifier.

ZONE, CLEAR Cleared area around an electromagnetic or capacitance fence. Its purpose is to minimize nuisance alarms caused by falling limbs, blowing rubbish, small animals, etc.

ZONE EXPANDER A device that allows more than one (usually two or four) individual zones to be monitored over a single pair of wires. The device is armed and powered form a main controller. Individual zones are either active or, if unused, placed out of service.

ZONED CIRCUIT A circuit which provides continual protection for parts or zones of the protected area while normally used doors and windows or zones may be released for access.

ZONES Smaller subdivisions into which large areas are divided to permit selective access to some zones while maintaining other zones secure and to permit pinpointing the specific location from which an alarm signal is transmitted.

ZOOM LENS An optical system in which the focal length or magnification is changed by the axial movement of one or more lens components while maintaining focus on a given object. It gives the effect of moving the camera to or from the subject.

ZOOM RATIO The ratio between the longest and shortest focal length of a single lens. For example, a 35 to 105 mm zoom lens would have a 3:1 zoom ratio.

3. Symbols.

4. Notes.

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