Federal standard

LUMEN/FT2 A unit of incident light. It is the illuminance on a surface one square foot in area on which a flux of one lumen is uniformly distributed, or the illuminance at a surface all points of which are at a distance of one foot from a uniform source of one candela.

LUMINANCE Luminous intensity (photometric brightness) of any surface in a given direction per unit of projected area of the surface as viewed from that direction, measured in foot‑lamberts (fl).

LUMINANCE SIGNAL That portion of the NTSC color television signal which contains the luminance or brightness information.

LUX A metric unit of measurement for light. One lux equals one lumen per square meter.

M

MACS See Maximum adjacent cut specification.

MAGNETIC ALARM SYSTEM An alarm system which will initiate an alarm when it detects changes in the local magnetic field. The changes could be caused by motion of ferrous objects such as guns or tools near the magnetic sensor.

MAGNETIC BURIED‑LINE SENSOR A passive sensor that comprises a buried wire loop and some detection logic. An intruder having ferromagnetic material crossing the loop will generate an electrical signal that is detected by the loop and the associated processing circuitry.

MAGNETIC CONTACT A type of sensor that protects a movable barrier or object, usually a door or window. The device consists of two parts: an enclosed magnet (actuating block) and an enclosed reed switch (contact block). Each half of the device is mounted close together; the switch on the door or window frame, and the magnet opposite the switch on the opening portion of the door or window. In operation, when the two devices are in close proximity, the magnet holds the reed switch closed (or open). Separating the two halves (by opening the door or window) removes the magnetic field causing the switch to open (or close) the circuit and initiate an alarm. Magnetic contacts are available with different gap specifications.

MAGNETIC FIELD The pattern of magnetic force lines surrounding a magnet, energized electromagnet or inductor. Also referred to as flux.

MAGNETIC FOCUSING A method of focusing an electron beam by the action of a magnetic field.

MAGNETIC LOCK A type of door lock that consists of an electromagnet and strike plate. The electromagnet is mounted in the door frame opposite the strike plate, which is mounted on the door. When current is applied, the strength of the magnetic attraction holds the door locked. Magnetic locks operate on low voltage (12 Vdc) and consume minimal power.

MAGNETIC REED SWITCH See Magnetic Contact.

MAGNETIC SENSOR A sensor that initiates an alarm when it detects a change of a given magnitude in a magnetic field.

MAGNETIC SWITCH A switch which consists of two separate units: a magnetically actuated switch, and a magnet. The switch is usually mounted in a fixed position (door jamb or window frame) opposing the magnet, which is fastened to a hinged or sliding door, window, etc. When the movable section is opened, the magnet moves with it, actuating the switch.

MAGNETIC CARD ACCESS A method of access control that uses magnetically encoded plastic cards, that are placed in or near magnetic card readers, for the purpose of controlling movement into the out of a secured area.

MAGNETIC SPOT CARD An access control card manufactured with a barium ferrite core containing an array of permanently magnetized spots. The magnetic spots correspond to an arrangement of magnetically activated switches or sensors in the card read head. The activation of specific switches or sensors indicates the card's code.

MAGNETIC STRIPE CARD A card used in magnetic strip reading systems. The cards have a narrow band of magnetic material applied on one side. Magnetic stripe cards are produced with either 300 or 4000 oersted material. Cards having 300 oersted material are the most common. Cards having a 4000 oersted stripe are used for higher security applications due to the stability of the magnetic material.

MAGNETICALLY ENCODED CARD A plastic card used for access control or other purposes that has a specific magnetic code embedded within, or encoded upon, the surface of the card. A magnetic card reader interprets the code and grants entry/exit upon input of proper criteria. Magnetically encoded cards include magnetic stripe, magnetic spot, and Wiegand Effect cards.

MAID'S MASTER KEY The master key in a hotel master key system given to the maid. It operates only cylinders of the guest rooms and linen closets in the maid's designated area.

MAIN ENTRY DOOR The most important common entry door in a building, which provides access to the building's lobby.

MAINFRAME COMPUTER A large capacity computer used as a central processing unit for a security monitoring and/or access control system. Mainframes are practical for larger integrated systems.

MAINTENANCE MASTER KEY See Engineer's Key.

MAISON KEY SYSTEM A keying system in which one or more cylinders are operated by every key (or relatively large numbers of different keys) in the system; e.g., main entrances or laundry areas of apartment buildings operated by all individual suite keys of the building. The term is derived from the French, maison meaning "house".

MAISON KEYING Use of a Maison key system.

MANCHESTER CODE See Biphase Code.

MANIPULATION KEY Any key other than a correct key which can be variably positioned and/or manipulated in a keyway to operate a lock or cylinder.

MANTRAP A booth or chamber with two or more remotely controlled doors through which an individual must pass to move from one area to another. Persons unable to produce proper authorization for a guard via a CCTV or other identification system are not allowed to pass and may be detained. Also called a video access booth when CCTV is employed.

MANUAL ACTIVE SWITCHER A manual CCTV camera switcher that employs active switching electronics and vertical interval switching to effect rapid and stable scene changes.

MANUAL ALARM STATION A signal transmitter with a pull type lever mounted in a conspicuous location. Pulling the lever closes a set of contacts and initiates an alarm. It is commonly used with fire systems, but can also be used in security applications where an accessible alarm station is required for panic or duress situations. It is classified as coded or noncoded. Noncoded manual alarm stations simply open or close a circuit and cannot be externally reset. Coded stations transmit a uniquely coded signal upon activation. Also called a pull station or fire alarm box.

MANUAL PASSIVE SWITCHER A CCTV camera switcher with no active electronic switching components. It accomplishes simple electrical switching using manually operated push buttons or switches. Manual switching generally causes some minor picture disturbance as the change is made from scene to scene.

MARK Presence of a signal. In telegraph or teletype communications a mark represents the closed condition, or current flowing. In digital communications, a mark represents a binary 1.

MASONRY Stone, brick, concrete, hollow tiles, concrete blocks, or other similar materials, bonded together with mortar to form a wall, pier, buttress, or similar member.

MASS STORAGE Relatively large volume storage, on line, and directly accessible to the computer's central processor or control unit.

MASTER See Master Key #1.

MASTER ANTENNA TELEVISION (MATV) MATV is used when several video display units or standard rf television receivers share a common antenna.

MASTER BLANK 1. See Multi‑section Key Blank. 2. See All‑section Key Blank.

MASTER BOX A municipal fire alarm signaling panel that transmits a coded signal to a fire station. Also called a city box.

MASTER CHIP See Master Pin #1.

MASTER CODE CARD 1. A special access control card which, when inserted in a self contained card reader, sets the code required by all cards in the system to activate that reader. 2. A universal access control card that contains a code that grants entry/exit at any card reader in a system.

MASTER COMBINATION A universal code for unlocking a digital mechanical lock. It has the same function as a master key.

MASTER CONTROL UNIT (MCU) The core of the subscriber's protective alarm installation, whether a local or silent alarm system, to which all subscriber sensors and switches are connected.

MASTER DISC 1. See Master Pin #1. 2. See Stepped Tumbler. 3. A special disc tumbler with multiple gates to receive a sidebar.

MASTER DISC TUMBLER A disc tumbler that will operate with a master key in addition to its own change key.

MASTER KEY 1. A key which operates all the master keyed locks or cylinders in a group; each lock or cylinder usually operated by its own change key. 2. To combinate a group of locks or cylinders such that each is operated by its own change key as well as by a master key for the entire group.

MASTER KEY CHANGES The number of different usable change keys available under a given master key.

MASTER KEY CONSTANT See Constant Cut #1.

MASTER KEYED Of or pertaining to a cylinder or group of cylinders which are or are to be combinated so that all may be operated by their own change key(s) and by additional key(s) known as master key(s).

MASTER‑KEYED LOCKS Locks which can be opened by a single master key.

MASTER KEYED ONLY Of or pertaining to a lock or cylinder which is or is to be combinated only to a master key.

MASTER KEYING See Master Key #2.

MASTER KEY SECTION 1. See Multi‑section Key Blank. 2. See All‑section Key Blank.

MASTER KEY SYSTEM 1. Any keying arrangement which has two or more levels of keying. 2. A keying arrangement which has exactly two levels of keying.

MASTER LEVER A lever tumbler which can align some or all other levers in its lock so that their gates are at the fence. It is typically seen in locks used on strorage lockers.

MASTER PIN 1. Usually a cylindrical shaped tumbler, flat on both ends, placed between the top and bottom pin to create an additional shear line. 2. A pin tumbler with multiple gates to accept a sidebar.

MASTER RING A tube shaped sleeve located between the plug and shell of certain cylinders to create a second shear line. Normally the plug shear line is used for change key combinations and the shell shear line is used for master key combinations.

MASTER RING LOCK/CYLINDER A lock or cylinder equipped with a master ring.

MASTER WAFER 1. See Master Pin #1. 2. See Stepped Tumbler. 3. A ward used in certain binary type disc tumbler key‑in‑knob locks.

MATCHING See Impedance Matching.

MATCHING NETWORK A circuit that accomplishes impedance matching. Matching networks maintain line supervision while permitting audio signals access to an alarm data line.

MATERIAL Any document, product or substance on or in which information may be recorded or embodied. Material shall include every thing, regardless of the item's physical character or makeup. Machinery, documents, devices, models, photographs, recordings, reproductions, notes, sketches, maps, and letters, as well as all other products, substances or materials, fall within the general term "material".

MATRIX An assemblage of electrical interconnections that code, decode or annunciate signals.

MATRIX PRINTER A printer that produces a character made of a matrix of small dots by advancing a printhead containing a group of points. The points strike the paper to form the character. Also known as a dot matrix printer.

MATRIX SWITCHER A switching device that uses electronic or electromechanical components to route input signals to predetermined outputs.

MAT SWITCH A flat area sensor used on open floors or under carpeting in pedestrian areas. It maybe sensitive over an area of a few square feet or several square yards. Also called an area mat or a floor sensor.

MATTE Also mat or matting. Used interchangeably to describe the creation of framing around a television picture, or the gray pebbling, half toning, or haloing of portions of a TV picture.

MATV See Master Antenna Television

MAXIMUM ADJACENT CUT DIFFERENTIAL See Maximum Adjacent Cut Specification.

MAXIMUM ADJACENT CUT SPECIFICATION The maximum allowable difference between adjacent cut depths.

MAXIMUM OPPOSING CUT SPECIFICATION The maximum allowable depths to which opposing cuts can be made without breaking through the key blade. This is typically a consideration with dimple keys.

McCULLOH LOOP A supervised metallic pair of wires that links several alarm system subscriber premises in a series. Loop resistance restricts the number of subscribers sharing one line. The usual number of protection areas on a single loop ranges between approximately 15 and 45.

MEANTIME BETWEEN FAILURE (MTBF) A statistical figure that represents the average time between failure of components or pieces of equipment for a given lot of identical devices.

MEAN TIME TO REPAIR (MTTR) A statistic that represents the average time between equipment or component failure and the completed repair of that unit.

MECHANICAL DOOR LOCK 1. A nonpowered mechanical locking device that requires either the entry of a push button sequence or a magnetic key to open. 2. An access control card reader that does not require external power to operate. Some mechanical door locks feature the capability for field modification of the unlocking code.

MECHANICAL FOCUS The focusing of a camera lens or tube by nonautomatic means, such as a cable and gear arrangement.

MECHANICAL LOCK A locking mechanism that does not require any electrical or electronic circuitry to operate, as opposed to an electromechanical lock. A true mechanical lock uses springs and rotating cams to move the major parts and the latch bolt. Opening is accomplished by using combinations of internal slides or tumblers, whereby, electromechanical locks use a solenoid to operate the latch bolt. Electronic locks are electromechanical locks with the addition of electronic keying circuitry.

MECHANICAL SWITCH A switch in which the contacts are opened and closed by means of a depression plunger or button.

MEETING STILE The vertical edge member of a door or horizontal sliding window, in a pair of doors or windows, which meets with the adjacent edge member when closed. See also Checkrails.

MEGAHERTZ(MHz) A term meaning one million hertz.

MEGGER A high range ohmmeter having a built‑in hand driven generator as a direct voltage source, used for measuring resistance and determining ground faults.

MEMORY The storage area for computer operating instructions and other pertinent system data that must be available for instant recall. Speed and capacity of a computer memory is a function of the data storage media used. Semiconductors and magnetic disks are two commonly used memory devices.

MENU A presentation of written or symbolic operational options from which an individual using a computerized system must select to initiate, continue or terminate a specific task.

MERCURY BATTERY Refers to a mercuric oxide battery. A relatively expensive battery that is excellent for compact circuitry applications. These batteries have a high energy density, but a comparatively lower shelf life.

MERCURY CONTACTS A pool of mercury in a vial that touches or disconnects contact wires when the vial is tilted. Used on windows, especially transoms.

MERCURY DROP CONTACT SWITCH A variation of the magnetic contact. A mercury drop contact switch uses a small amount of mercury to complete a circuit. The mercury contact design eliminates many of the corrosion and magnetic buildup problems associated with conventional magnetic contacts.

MERCURY FENCE ALARM A type of mercury switch which is sensitive to the vibration caused by an intruder climbing on a fence.

MERCURY SWITCH A switch that completes or opens an electrical circuit by the movement of a drop of mercury between contact points. The mercury moves by tilting or vibrating. Mercury switches are used in vibration and fence sensors.

METAL DETECTOR A fixed, portable, or hand held device used to detect the presence of metallic objects. These devices are usually designed to detect only metal that is of sufficient volume to produce a warning causing a further investigation for a concealed weapon. Some metal detectors operate by creating a balanced magnetic field between transmission and receive coils. The movement of a metal object through the field causes an induced voltage in the receiving coils. The imbalance initiates an alarm. Sensitivity is a function of coil characteristics. Other metal detectors use radio frequency (rf) transmission to create eddy currents in metal objects passing the detector, and a receiver with control circuitry to catch the rf pulse generated by the eddy current's decay.

METAL‑MESH GRILLE A grille of expanded metal or welded metal wires permanently installed across a window or other opening in order to prevent entry through the opening.

METALLIC PHONE LINE A phone line made of metal wire (usually copper) and used for point‑to‑point transmission. Nonmetallic telephone transmission media include microwaves and fiber optics.

MHz See Megahertz.

MICROCOMPUTER A small capacity computer with limited memory and functions. It is used for small to mid‑sized computerized security systems, and is usually programmed in an upper level language such as BASIC.

MICROPHONE CABLE A special shielded cable that connects a microphone to an amplifier.

MICROPHONE, CONTACT Microphone which can be mounted directly on a protected wall, safe, etc. The microphone is usually insensitive to ambient room noises and detects the sound of the wall or safe being breached to activate an alarm circuit.

MICROPHONICS Audio frequency noise caused by the mechanical vibration of elements within a system or component.

MICROPROCESSOR A complete electronic circuit that has been reduced and placed on a tiny chip of silicon. It is the central processing unit (CPU) and one of the major components of a microcomputer. The use of microprocessors has led to important developments in electronic security products.

MICROWAVE 1. Radio waves that are less than 30 centimeters in length. Microwave frequencies are usually 1000 MHz and higher. 2. A type of sensor that uses microwaves to detect motion. 3. A data transmission media for alarm data.

MICROWAVE SENSOR An active intrusion sensor that detects the movement of a person or object through a pattern of microwave energy. Microwave sensors are classified as either monostatic, bistatic, or terrain following. In general, comparative circuitry in a monostatic sensor uses the Doppler Effect to recognize movement within a protected area. Bistatic sensors operate on a beambreak principle. Terrain following microwave sensors are essentially bistatic sensors with antenna configurations that are not overall line‑of‑sight. Monostatic sensors are typically designated for indoor use; bistatic and terrain following sensors are normally used for outdoor applications.

MIL SPEC 1. Term for Military Specification. U.S. Government standards that are documented in order to standardize and specify Government purchased equipment. 2. Any equipment or component that meets or exceeds military specifications.

MILL FINISH The original surface finish produced on a metal mill product by cold rolling, extruding or drawing.

MILLING (OF A KEY) 1. See Key Section. 2. See Key Milling.

MILLWORK Generally, all building components made of finished wood and manufactured in millwork plants and planing mills. It includes such items as inside and outside doors, window and door frames, cabinets, porch work, mantels, panel work, stairways, molding, and interior trim. It normally does not include flooring, ceiling, or siding.

MIMIC DISPLAY An annunciator board. It usually comprises LEDs or incandescent bulbs arranged on a display panel.

MINIATURE MAGNETIC CONTACT A small magnetic contact designed for tight spaces and improved concealment. It operates on the same principles as standard size magnetic contacts.

MINICOMPUTER A medium capacity computer that falls between a microcomputer and a large mainframe in scope and function.

MIS‑CUT 1. Of or pertaining to a key which has been cut incorrectly. 2. A mis‑cut key.

MK See Master Key.

MK SECTION See Master Key Section.

MK'd See Master Keyed.

MK'd ONLY See Master Keyed Only.

MNEMONIC CODE Short groups of letters or symbols that are used to represent machine code. Mnemonic code is used by computer programmers to assist in the recognition of low level language codes.

MOBILE ANNUNCIATOR An annunciator or mimic display designed for mounting in a vehicle. System status information is received via an rf link from a central monitoring station.

MOCS See Maximum Opposing Cut Specification.

MODE An operational condition in which a security system responds to specific inputs with a predetermined response. For example, placing a system into a programming mode allows the system to be reconfigured.

MODELING/SIMULATION Using a mathematically derived procedure to test the characteristics of a system without actually performing the procedure on the system itself. Modeling helps to predict the probability of success when engaging the real system.

MODEM Acronym for Modulator/Demodulator. A modem converts digital information into audio tones for fsk transmission over standard voice grade telephone lines. The signal is converted back to digital information at the receiving end. Using modems, alarms may be remoted from distant points to a central receiving station.

MODULATED PHOTOELECTRIC SENSOR A sensor that uses a modulated beam of light (usually infrared) between a transmitter and receiver to detect an intruder. The receiver is only sensitive to light modulated at the frequency of the transmitting unit. In addition to causing an alarm if the beam is broken, the receiver initiates an alarm if it does not receive light that has been correctly modulated for that receiver. In this way, the possibility of defeating the sensor by introducing another light source is reduced.

MODULATION The process or results of the process, whereby some characteristic of one signal is varied in accordance with another signal. The modulated signal is called the carrier. The carrier may be modulated in three fundamental ways by varying the amplitude, called amplitude modulation (AM),by varying the frequency, called frequency modulation (FM) and by varying the phase, called phase modulation.

MODULATOR A device that incorporates an informational signal with a carrier frequency for the purpose of transmission.

MODULATOR/DEMODULATOR See Modem.

MODULE A self contained unit or component that is part of a larger system. Modules allow ease of replacement during repair or reconfiguration by substitution.

MOGUL CYLINDER A very large pin tumbler cylinder whose pins, springs, key, etc. are also proportionally increased in size. It is typically used in prison locks.

MOIRE In television, the spurious pattern in the reproduced picture resulting from interference beats between two sets of periodic structures in the image.

MOISTURE DETECTOR A sensor that causes a contact closure when sufficient moisture creates an electrical bridge. It is used to detect hazardous or problematical moisture buildup in equipment cabinets or electrical conduits.

MOMENTARY DRY CONTACT A switch that activates only during the duration of the fault state.

MONEY CLIP A sensor designed to initiate an alarm when paper money is removed from a special detection unit in a cash drawer. It is sometimes referred to as a currency trap.