JAOMAD Glossary G:
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z Intro
G—Thermocouple type for Tungsten vs. Tungsten 26% Rhenium; also: formerly meant "Gauging"(dimensional) when used in first alpha character position of ISA instrument function tag, still means (sight) "Glass," or "Viewing Device" when used in succeeding position [see ANSI/ISA S5.1-1984 (R1992)]; also: G(uppercase) in math is abbreviation "giga-" for 109, once called kilomega (kM).
G-Glass—In construction of glass bulb type pH sensors, this is used for membranes of electrodes for processes where nominal pH value varies around pH 7; since this type of glass has wide application range it is also termed "general purpose" glass; see E-, L-, S-Glass.
G1—In equipment corrosion specifications, less than 300 Å/month copper corrosion (of electrical terminals) as one measure of mild environmental contamination, as defined in ISA standard S71.04.
G2—In equipment corrosion specifications, less than 1000 Å/month copper corrosion (of electrical terminals) as one measure of moderate environmental contamination, as defined in ISA standard S71.04.
G3—In equipment corrosion specifications, less than 2000 Å/month copper corrosion (of electrical terminals) as one measure of harsh environmental contamination, as defined in ISA standard S71.04.
GX—In equipment corrosion specifications, equal to or greater than 300 Å/month copper corrosion (of electrical terminals) as one measure of severe environmental contamination, as defined in ISA standard S71.04.
GaAs—Gallium Arsenide.
Gain—Increased signal power, usually result of amplification; opposite of attenuation; ratio of output to input voltage, current or power.
Gain Accuracy—Measure of deviation of gain of amplifier from ideal gain.
GAL—Generic Array Logic, same as Programmable Array Logic device, but AMD® made "PAL" a tradename; another term is PEEL.
Gamma(g)—In digital graphic video, measures contrast that affects midtones of image; adjusting allows change in brightness values of middle range gray tones without altering shadows and highlights.
Gap Loss—Loss resulting from end separation of two axially aligned optical fibers.
Gate Array—Unfinished electronic chip with electronic components that have not been connected; chip is completed by designing and adhering ; top metal layers which provide interconnecting pathways, this final masking stage is less costly than designing the chip from scratch; array is made up of basic cells, each cell containing some number of transistors and resistors depending on the vendor; by using cell library (gates, registers, etc.) and macro library (more complex functions), customer designs chip, and vendor's software generates masks that connect the transistors.
Gatekeeper—Computer server that translates user names into physical addresses for data, voice and videoconferencing over LANs and Internet; can also be used to provide call authorization and accounting information; also: in selling, the person who controls access to those who make the decisions.
Gateway—Conceptual or logical network station that serves to interconnect two otherwise incompatible networks, network nodes, subnetworks, or devices; performs protocol conversion operation across numerous communications layers; much more complicated than bridge, ISO defines it as device which traverses all seven layers; current, sloppier definition describes it as any mechanism providing access to another system.
Gauge Factor—Ratio of resistance to relative change in length of piezo resistive strain gauge.
Gauge Pressure—Force per unit area exerted by fluid using atmospheric pressure as zero reference; absolute pressure minus atmospheric pressure.
GAW—Guided Acoustical Wave type of touchscreen which channel acoustical energy into full volume of screen material; compare with SAW.
GB—Gigabyte; see definition.
Gb—Gigabit; 1,073,741,824 bits.
GBIB—General Purpose Interface Bus.
GC—Gas Chromatography, Gas Chromatograph.
GCI—Guest Computer Interface.
GCR—Gray Component Replacement; color separation control technique in color screen displays and printing.
GDDM—Graphic Data Display Manager for presentation of graphics.
GDS—Graphic Data System.
GDT—Gas Discharge Tube; used for overvoltage protection and energy transfer switches.
GD&T—Geometric Dimensioning & Tolerancing.
GE Genius—I/O protocol of GE-Fanuc®.
GEMS—Global Enterprise-wide Management System; beyond Enterprise Resource Planning, this includes connectivity from a corporation to the companies of suppliers as well as customers, often over the Internet, to manage the flow of business requirements and products among all of them. See ERP.
Generalized Multiprotocol Label Switching (GMPLS)—In a WDM optical networking system, the ability to route a data transmission based on the wavelength of light that carries it; The routing device only analyzes wavelengths (light frequencies) to make its forwarding decision rather than inspecting fields within each packet; GMPLS adds numerous enhancements to MPLS in order to support optical networks; was originally known as Multiprotocol Lambda Switching, the "L" in the acronym MPLS was the Greek lambda; See MultiProtocol Label Switching & Wavelength Division Multiplexing.
Generation—In analog editing of video tape, each copy creates another generation, and loses signal quality, hence the term "generation loss" or "to go down another generation."
Generator—Considered in EPA (U.S.) regulations as person, group, or organization whose activities generate hazardous waste.
Genetic Algorithm—Reiterative computing method developed by John Holland in the 1970s to more quickly solve complex problems using properties of natural selection found in biological evolution to adjust to changing environments; uses simple encoding and reproduction mechanisms through simple manipulation of chromosomes (strings of 1s &0s) to develop "new genes" (solutions) through parent selection, mutation, and crossover to create children different than their parents; by constantly comparing the multiple solutions with the desired result, it will accept and reject various chunks of code and try new combinations from those chunks which remain, until it finds the optimum fit.
Genetic Caching—Genetic caching takes caching, storage of Web content on the edge of network close to end users, a step further by adding advanced mathematical theory by considering information such as how far away users are, what type of modem they're using and their browser version, and optimizes page delivery according to these characteristics to better use processing power of available CPUs to deliver optimal performance.
GFCI—Ground Fault Circuit Interrupter, which protects humans from electrical shock.
GFLOPS—Giga FLoating Point Operations Per Second.
GHIM—Good Heavens, It's Monday. J
GHz—GigaHertz; see below.
GIF—[pronounced: jiff] Graphics Interchange Format; method of saving graphics in electronic memory, used for exchanging data between computers; further: See Clear GIF.
Gigabyte—Gbyte, Gig, GB; 1,073,741,824 bytes; 1024 megabytes (230 bytes); basic unit of measurement of mass storage; also: used in describing data transfer rates (primarily parallel) as function of time (Gbps).
GigaFlops—One billion (109) FLoating Point Operations Per Second.
Gigahertz (GHz)—Unit of measurement equaling one billion cycles per second.
Gilder's Law—Suggested by George Gilder, prolific author and prophet of new technology age which says that total bandwidth of communication systems triples every twelve months; new developments seem to confirm that bandwidth availability will continue to expand at rate supporting Gilder's Law; see also Moore’s Law & Metcalf’s Law.
GIS—Graphic Information System; computer system for presenting data in graphic form; also: Geographic Information System, an emerging computer technology being used to manage industrial facilities.
GIW—Gain In Weight; generally measured in processes which create change in density of product or volume of product in some vessel during operations on product.
GKS—Graphical Kernel System; device-independent graphics language for 2-D, 3-D and bitmapped graphics images which allows graphics applications to be developed on one system and easily moved to another with minimal or no change; was first true standard for graphics applications programmers and has been adopted by both ANSI and ISO.
Global Positioning System—Satellite-based radio navigation system run by the U.S. Department of Defense, officially known as NAVSTAR GPS; designed so that signals from at least four satellites would be on the horizon at all times, which is sufficient for the GPS receiver to compute the current latitude and longitude (map location) and elevation anywhere on earth to within a range of 15 to 70 feet.
Global System for Mobile Communications—Digital cellular phone technology developed in the 1980s based on TDMA that is the predominant system in Europe, but also used worldwide; operates in the 900 MHz and 1.8 GHz bands in Europe and the 1.9 GHz PCS band in the U.S. Based on a circuit-switched system that divides each 200 kHz channel into eight 25 kHz time slots, GSM defines the entire cellular system, not just the TDMA air interface.
GLP—Good Laboratory Practice; regulations by FDA (U.S.) for non clinical laboratory studies.
GLS—Global Logistics System.
GMA—Gas Metal Arc (Welding).
GMC—General Motion Control(ler).
GMM—Graphical MultiMeter; multiple electrical signal tester which can display waveforms.
GMP—Good Manufacturing Practice; regulations by FDA (U.S.) for medical devices.
GMPLS—Generalized MultiProtocol Label Switching; see definition.
GMR—Giant MagnetoResistive; changes in electrical resistance in materials composed of alternating thin layers of metallic elements, or magnetic metals separated by nonmagnetic “spacers,” used in memory storage devices for much more capacity in disk drives than conventional magnetoresistive methods.
GMT— Greenwich Mean Time, former term for UTC; see definition of Universal Time Coordinated.
GND—GrouND; usually chassis ground, but can be used for earth ground electrical potential.
GNU—[pronounced: gee-noo]; Interestingly, short for GNU's NOT UNIX, a UNIX-compatible software system developed by the Free Software Foundation (FSF), to produce software that is non-proprietary so that anyone can download, modify and redistribute GNU software; only restriction is that users cannot limit further redistribution; GNU Manifesto was published in March 1985 issue of Dr. Dobb's Journal but GNU project started a year and a half earlier when Richard Stillman was trying to get funding to work on his freely distributable editor, EMACS at Massachusetts Institute of Technology; Linux systems rely heavily on GNU software and in the past, GNU systems used the Linux kernel, a close connection that has led some people to mistakenly equate GNU with Linux which are actually quite separate; FSF is developing a new kernel called HURD to replace Linux kernel in GNU systems; see HURD; EMACS.
Gopher—Internet protocol that directly preceded WWW, created by University of Minnesota, more basic system than HTTP; also: software tool used for finding information over the Internet when address holding information is unknown; using menu options that take requester through hierarchical directories, and in doing so will "go for" it; also: person whose job is to "go for" it. J
GOSIP—Government Open Systems Interconnection Profile; U.S. Federal Information Processing Standard 146 which defines set of open system communication protocols that allow different makes of computers to communicate, and users of different applications on these systems to exchange information.
Gotchas—Vendor named category of control system specifications written by users & system consultants which have same effect as smokescreens but use some single detail to define the unique; usually used to force selection to one favorite vendor; see also Dowatchados, Druthers, Expectifications, Ropushers, Smokescreens, Stickits, Stonecutters, Wannagirls. J
Gowpen—Amount of water you can hold by cupping your hands. K
GP—Gauge Pressure.
GPD—Gas Plasma Displays that emit glow when exited with small voltage; type of liquid crystal displays (LCD).
GPH—Gallons Per Hour (volumetric flow rate).
GPIB—General Purpose Interface Bus; IEEE488 standard; parallel, multiport, 300Kbs to 1Mbs, 15-28 stations on up to 50 feet; originally developed by Hewlett-Packard as HP-IB for laboratory instrumentation.
GPM—Gallons Per Minute (volumetric flow rate).
GPRS—General Package Radio Service; wireless digital communication standard which allows communication with very high band with (115 Kbytes / s); as of 2000, is only wireless package oriented standard.
GPS—Global Positioning System; see definition.
Graceful Degradation—Method of keeping process running, though component failures may degrade degree of automation and sophistication.
Graded Index Fiber—Optical fiber whose core has non uniform index of refraction; core is composed of concentric rings of glass whose refractive indices decrease from center axis to reduce modal dispersion and thereby increase fiber bandwidth.
GRAFCET—GRAphe Fonctionnel de Commande Etape/Transition (in English, step transition function charts); created in 1979 by French Association for Economical and Applied Cybernetics; popular subset of Sequential Function Chart (SFC) providing diagrammatic representation of program sequences and supporting alternative sequence selections and parallel sequences; basic elements are steps and transitions, originally an enhancement to PLC ladders.
Grantartic —Cold, isolated place where research & development projects dwell without funding. J.
Grapheme—Smallest unit of written language, generally single letter for a vowel or consonant, sometimes combination such as "th" or "ch."
Graphical User Interface(GUI)—Operating system or environment that displays program choices & options on screen as icons (pictures or symbols) & often windows as interface between computer systems and people; selections typically made with mouse or trackball (point & click); Invented at Xerox® in 1970's, was first used on Apple® Macintosh® & later on Microsoft® Windows™, Digital Research® GEM™, and X-Windows.
Graphics Object—Visually oriented screen view item, such as scroll bar, bit-map, icon that is used in presentation of some application interface.
Gravity Convection Oven—Oven in which there is no mechanical means of circulating air in oven chamber.
Gray Balance—In composition of screen displays and printing, dot values or densities of cyan, magenta, and yellow that produce neutral gray.
Ground—Electrical connection or common conductor that, at some point, connects to earth; negative side of dc power supply; reference point for electrical system; called “Earth” by many.
Ground Loop Noise—Noise that results when equipment is grounded at points having different potentials and thereby create unintended current path.
Grounded Junction—Form of thermocouple construction where measuring junction is electrically connected to its protective sheath so that both have same potential.
Group Addressing—In transmission, use of address that is common to two or more stations; on multipoint line, where all stations recognize addressing characters, but only one station responds.
Gry—Equivalent to 120th of an inch, comes from Greek word for speck of dirt under fingernail; proposed for use in England in 1813 as part of plan to make all linear measurements decimal based. K
GS—Gas Supply.
GSM—Global System for Mobile communications; see definition.
GTA—Gas Tungsten Arc (Welding).
GTL—Gas To Liquids.
GTPBGA—Glob Top Plastic Ball Grid Array.
GTO—Gate Turn Off thyristor.
Guest (Computer)—In process control, use of computer which is not primary or controlling computer, nor used to configure some multiple part system, but provides services auxiliary to the basic control; such functions can be historical and archival data collection, library of application programs, background calculations, etc.; term originally used somewhat tongue-in-cheek by Sam Herb and Scotty Moore in their first edition of Understanding Distributed Process Control in 1981 for system with a computer that is connected but not required for process control system startup or operation; see Host.
GUI—[pronounced: gooey] Graphical User Interface; operating system or environment that displays program choices & options on screen as icons (pictures or symbols) & often windows; selections typically made with mouse or trackball (point & click); Invented at Xerox® in 1970's, was first used on Apple® Macintosh® & later on Microsoft® Windows™, Digital Research® GEM™, and X-Windows.
Guided Acoustical Wave (GAW)—Type of touchscreen which channel acoustical energy into full volume of screen material; compare with SAW.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z Intro