air lock GI An opening through which air hp See air horsepower out of an enclosed spac airflow pipe ENG A tube through which air is fresh air with hot exhaust gases in the e以h Abbrevi chage TENG)i A devic- char ie combustion essure. 2. A device that compares the shape air inlet air-conditioning sys- ce by measuring the rate of passage of air be- rgap ELECTR 1. a ga on of either inside or outside air. 'er lin,let 2. A spark gap consisting of ENG A device that uses a thin, flat jet coating from freshly parts. 2. In plastic extrusion coating, the dis- air-knif left on paper after treatment with an air knife air-lance ENGI To direct a pressurized-air llations.as upplies a plumbing fixture (such as a tank or in boiler-wall cleani brought into or discharged from the building urposes of ventilation. ' er grad -in I rless spraying ENG The spraying of paint by air hammer See pneumatic hammer. 'er ham neans of high fluid pressure and special equip- ment. Also known as hydraulic spr in which an air-handling un vides part of the treatment of the air. 'er mbly of air-co ne treatment of air before it is distrib- a well; the lower end of the pipes is of air and water which rocating motion and air motors for ell; also used to mowe corrosive liquids. bo flings, and sand. Also known as air lift. 'er air horn MECH ENG In an automotive engine, air line ENGI A fault, in the form of an elon- portion of the carburetor barrel gated bubble, in glass tubing. IG A duct, ho nose, or pipe ntrolled by the choke plate and the throttle that supplies compressed air to a pneumatic tool NG 1. A chamber capable of bein in a fan, blower, compressor, or vac- um pump. Abbreviated air hp. I'er hors reen two places of different pressure, such as etween an altitude chamber and the outside
air lock airflow orifice [ENG] An opening through which air hp See air horsepower. air moves out of an enclosed space. { erflo¯ air-injection reactor [MECH ENG] A unit in- o˙rəfəs } stalled in an automotive engine which mixes airflow pipe [ENG] A tube through which air is fresh air with hot exhaust gases in the exhaust conveyed from one location to another. { er manifold to react with any gasoline that has flo¯ pı¯p } escaped unburned from the cylinders. Abbreviair-fuel mixture [MECH ENG] In a carbureted ated AIR. { er in¦jekshən re¯aktər } gasoline engine, the charge of air and fuel that air-injection system [MECH ENG] A device that is mixed in the appropriate ratio in the carbure- uses compressed air to inject the fuel into the tor and subsequently fed into the combustion cylinder of an internal combustion engine. chamber. { er fyu¨ l mikschər } Also known as thermactor. { er in¦jekshən air gage [ENG] 1. A device that measures air sistəm } pressure. 2. A device that compares the shape air inlet [MECH ENG] In an air-conditioning sysof a machined surface to that of a reference sur- tem, a device through which air is exhausted face by measuring the rate of passage of air be- from a room or building. { er ¦inlet } tween the surfaces. { er ga¯j } air-inlet valve [MECH ENG] In a heating/air-conair gap [ELECTR] 1. A gap or an equivalent filler ditioning system of a motor vehicle, a valve in of nonmagnetic material across the core of a the plenum blower assembly that permits selecchoke, transformer, or other magnetic device. tion of either inside or outside air. { er ¦inlet 2. A spark gap consisting of two electrodes sepa- valv } rated by air. 3. The space between the stator air knife [ENG] A device that uses a thin, flat jet and rotor in a motor or generator. [ENG] of air to remove the excess coating from freshly 1. The distance between two components or coated paper. { er nı¯f } parts. 2. In plastic extrusion coating, the dis- air-knife coating [ENG] An even film of coating tance from the opening of the extrusion die to left on paper after treatment with an air knife. the nip formed by the pressure and chill rolls. { er ¦nı¯f ko¯ diŋ } 3. The unobstructed vertical distance between air-lance [ENG] To direct a pressurized-air the lowest opening of a faucet (or the like) which stream to remove unwanted accumulations, as supplies a plumbing fixture (such as a tank or in boiler-wall cleaning. { er lans } washbowl) and the level at which the fixture will air leakage [MECH ENG] 1. In ductwork, air overflow. { er gap } which escapes from a joint, coupling, and such. air grating [BUILD] A fixed metal grille on the 2. The undesired leakage or uncontrolled pasexterior of a building through which air is sage of air from a ventilation system. { er brought into or discharged from the building for le¯ kəj } purposes of ventilation. { er gra¯diŋ } airless spraying [ENG] The spraying of paint by air hammer See pneumatic hammer. { er ham means of high fluid pressure and special equip- ər } ment. Also known as hydraulic spraying. air-handling system [MECH ENG] An air-condi- { erləs spra¯iŋ } tioning system in which an air-handling unit pro- air lift [MECH ENG] 1. Equipment for lifting vides part of the treatment of the air. { er slurry or dry powder through pipes by means of ¦handliŋ sistəm } compressed air. 2. See air-lift pump. { ¦er ¦lift } air-handling unit [MECH ENG] A packaged as- air-lift hammer [MECH ENG] A gravity drop sembly of air-conditioning components (coils, hammer used in closed die forging in which the filters, fan humidifier, and so forth) which pro- ram is raised to its starting point by means of vides for the treatment of air before it is distrib- an air cylinder. { erlift hamər } uted. { er ¦handliŋ yu¨nət } air-lift pump [MECH ENG] A device composed air heater See air preheater. { er he¯dər } of two pipes, one inside the other, used to extract air-heating system See air preheater. { er he¯d water from a well; the lower end of the pipes is iŋ sistəm } submerged, and air is delivered through the inair hoist [MECH ENG] A lifting tackle or tugger ner pipe to form a mixture of air and water which constructed with cylinders and pistons for recip- rises in the outer pipe above the water in the rocating motion and air motors for rotary well; also used to move corrosive liquids, mill motion, all powered by compressed air. Also tailings, and sand. Also known as air lift. { er known as pneumatic hoist. { er ho˙ ist } lift pəmp } air horn [MECH ENG] In an automotive engine, air line [ENG] A fault, in the form of an elonthe upper portion of the carburetor barrel gated bubble, in glass tubing. Also known as through which entering air passes in quantities hairline. [MECH ENG] A duct, hose, or pipe controlled by the choke plate and the throttle that supplies compressed air to a pneumatic tool plate. { er ho˙rn } or piece of equipment. { er lı¯n } air horsepower [MECH ENG] The theoretical air-line lubricator See line oiler. { er lı¯n lu¨ (minimum) power required to deliver the speci- brəka¯dər } fied quantity of air under the specified pressure air lock [ENG] 1. A chamber capable of being conditions in a fan, blower, compressor, or vac- hermetically sealed that provides for passage beuum pump. Abbreviated air hp. { er ho˙rs tween two places of different pressure, such as pau˙ər } between an altitude chamber and the outside 15
air-lock strip or between the outside atmosphere airportengineering CIv ENG The planning, de- load ing servicing, main- of a molded plastic part that results fre air trapped between the surface of the mold and ight. (er, prof I air meter ENGl A device that measures the flow air propeller IMECH ENGI A rotating fan for of air, or gas, expressed in volumetric or weigl ce or for adding air to an insisting essen- 叫aL ly of a reciprocating chisel or pick, driven Removal of particu units. such as an air mileage indicator. I'er airraid she lter Scr engn a cham ber, often un- air-mixing plenum ENG In an air-condi- ng people against air attacks. lating air is mixed with air from outdoors. ' er sed bot store the compressed ai or particular industrie air motor MEC ies. I 'er man- -trin l tre to be equalized in the system. i'er ri, se- air register ENGI A device attached to an air- a rotor or the movement of a piston. I'er the discharge of air into the space to be heated ECH ENGI In an automotive en- gine, a device for supplying air to the air-injec- ing airflow, as in the burner of a furnace. air reheater MECH ENG In a heating system to the air circulating 正 an ai dod ironing air release valve MECH ENG!'A valve, us air-permeability test ENG A test for the portland cement. 'er, por- me.a'bil-3- forces and wear on buildings and other struc- air ring ENGI In plastics forming. a circular flare ENGI A flare. often air pocket occupied by a liquid. Also known as air degree of air cleanliness. I 'er pa'lu shan kan bile, which is designed to utilize the dynamic ressure of the airstream to maintain a flow of airport ICV ENGI Terminal facility used for air- air. ',ski air screw MECH ENGI A screw propeller that for handling passengers and cargo and vicing aircraft. Also known as aerodrome. air-seasoned ENGI Treated by exposure to air uality. ('er ,sezand 16
air-lock strip atmosphere, or between the outside atmosphere airport engineering [CIV ENG] The planning, deand the work area in a tunnel or shaft being sign, construction, and operation and mainteexcavated through soil subjected to water pres- nance of facilities providing for the landing and sure higher than atmospheric. Also known as takeoff, loading and unloading, servicing, mainlock. 2. An air bubble in a pipeline which im- tenance, and storage of aircraft. { erpo˙rt en pedes liquid flow. 3. A depression on the sur- jəniriŋ } face of a molded plastic part that results from air preheater [MECH ENG] A device used in air trapped between the surface of the mold and steam boilers to transfer heat from the flue gases the plastic. { er la¨ k } to the combustion air before the latter enters the air-lock strip [BUILD] The weather stripping furnace. Also known as air heater; air-heating which is fastened to the edges of each wing of system. { er pre¯he¯dər } a revolving door. { airproof See airtight. { erpru¨ f } er la¨ k strip } air meter air propeller [MECH ENG] A rotating fan for [ENG] A device that measures the flow moving air. { er prəpelər } of air, or gas, expressed in volumetric or weight air pump [MECH ENG] A device for removing air units per unit time. Also known as airometer. from an enclosed space or for adding air to an { er me¯dər } enclosed space. { er pəmp } air mileage indicator [ENG] An instrument on air puncher [ENG] A machine consisting essen- an airplane which continuously indicates mile- tially of a reciprocating chisel or pick, driven by age through the air. { ¦er mı¯lij indəka¯dər } air. { er pənchər } air mileage unit [ENG] A device which derives air purge [MECH ENG] Removal of particulate continuously and automatically the air distance matter from air within an enclosed vessel by flown, and feeds this information into other means of air displacement. { er pərj } units, such as an air mileage indicator. { er air-raid shelter [CIV ENG] A chamber, often un- mı¯lij yu¨nət } derground, provided with living facilities and air-mixing plenum [MECH ENG] In an air-condi- food, for sheltering people against air attacks. tioning system, a chamber in which the recircu- { ¦er ra¯d ¦sheltər } lating air is mixed with air from outdoors. { er air receiver [MECH ENG] A vessel designed for miksiŋ ple¯nəm } compressed-air installations that is used both air monitoring [CIV ENG] A practice of continu- to store the compressed air and to permit pres- ous air sampling by various levels of government sure to be equalized in the system. { er rise¯ or particular industries. { er ma¨nətriŋ } vər } air motor [MECH ENG] A device in which the air register [ENG] A device attached to an air- pressure of confined air causes the rotation of distributing duct for the purpose of controlling a rotor or the movement of a piston. { er the discharge of air into the space to be heated, mo¯ dər } cooled, or ventilated. { er rejəstər } air nozzle [MECH ENG] In an automotive en- air regulator [MECH ENG] A device for regulat- gine, a device for supplying air to the air-injec- ing airflow, as in the burner of a furnace. { ¦er tion reactor. { er na¨zəl } ¦regyəla¯dər } airometer [ENG] 1. An apparatus for both hold- air reheater [MECH ENG] In a heating system, ing air and measuring the quantity of air admit- any device used to add heat to the air circulating ted into it. 2. See air meter. { era¨mədər } in the system. { ¦er re¯¦he¯dər } air outlet [MECH ENG] In an air-conditioning air release valve [MECH ENG] A valve, usually system, a device at the end of a duct through manually operated, which is used to release air which air is supplied to a space. { er au˙tlət } from a water pipe or fitting. { er ri¦le¯s valv } air-permeability test [ENG] A test for the meas- air resistance [MECH] Wind drag giving rise to urement of the fineness of powdered materials, forces and wear on buildings and other struc- such as portland cement. { ¦er pərme¯əbilə tures. { er rizistəns } de¯ test } air ring [ENG] In plastics forming, a circular airplane flare [ENG] A flare, often magnesium, manifold which distributes an even flow of cool that is dropped from an airplane to illuminate air into a hollow tubular form passing through a ground area; a small parachute decreases the the manifold. { er riŋ } rate of descent. { erpla¯n fler } air sampling [ENG] The collection and analysis air pocket [ENG] An air-filled space that is nor- of samples of air to measure the amounts of mally occupied by a liquid. Also known as air various pollutants or other substances in the air, trap. { er pa¨ kət } or the air’s radioactivity. { er sampliŋ } air-pollution control [ENG] A practical means of air scoop [DES ENG] An air-duct cowl projecting treating polluting sources to maintain a desired from the outer surface of an aircraft or automodegree of air cleanliness. { ¦er pəlu¨shən kən bile, which is designed to utilize the dynamic tro¯ l } pressure of the airstream to maintain a flow of airport [CIV ENG] A terminal facility used for air- air. { er sku¨ p } craft takeoff and landing and including facilities air screw [MECH ENG] A screw propeller that for handling passengers and cargo and for ser- operates in air. { er skru¨ } vicing aircraft. Also known as aerodrome. air-seasoned [ENG] Treated by exposure to air { erpo˙rt } to give a desired quality. { er se¯zənd } 16
rasher [MECH ENG A device that uses eries of cycles in which they are first suspended from others of er, sep rad- lution of c a ndergo a drying knot ster process. I'or sa spen shan in, kap ventilation for windows. Also known as air well er shaft) air-suspension system MECH ENG Parts of at shot lENGI A shot prepared ith the explosive for the purpose of lessen Airslide conveyor MECH ENG An air-activated wheels over irregularities. a degree which will permit it to air flow on a slight indie by the force of gravity. es instead of using elemental sulfur. air in a wall for sulation. I 'er spas sually a pitot tube, mounted changer, expander, and refrigerating core. ('er eiving the static and dynamic pressures of th used by the airspeed indicator, 'er, sped ai speed indicator ENG A device that com- engers and space for administrative functions. serves ch th ure or tainer that includes an elastomeric bellows or contained in a bulb placed in the space. diaphragm. I'er sprin 1 o A thermodynamic airtight EI emitting the passage of air. cycle in which the working fluid is considered to so known as airproof. ier, tTt I dous air nd 492R and a ratio of specific heats of 1: 4. tak- siks I I A U-shaped pipe filled with See air starting valve G A device air starter. fresh air by le tube. Also known as air-supply mas ganicsubstances from the water. ('er strip in) air-tube clutch fitted with air-supply mask See air-tube breathing apparatus. a tube whose inflation causes the dutch to Ier so'plf, mask gage, and deflation, to disengage. I'er tub r valy ECHENG A valve that automatically rrying pipe w nd determining their ntemal pressure drops below atmospheric. air surveillance radar ENGI Rada 点一 air vessel IENG] 1. An enclosed volume of uspension encapsulation CI echnique for microencapsulation of various air washer MECH ENG 1. A device for cooling types of solid particles; the particles undergo a nd cleaning air in which the entering warm 17
air washer air separator [MECH ENG] A device that uses series of cycles in which they are first suspended an air current to separate a material from another by a vertical current of air while they are sprayed of greater density or particles from others of with a solution of coating material, and are then greater size. { ¦er sepə¦ra¯dər } moved by the airstream into a region where they air shaft [BUILD] An open space surrounded by undergo a drying treatment. Also known as the walls of a building or buildings to provide Wurster process. { ər sə¦spenshən inkap ventilation for windows. Also known as air well. səla¯shən } { er shaft } air-suspension system [MECH ENG] Parts of an air shot [ENG] A shot prepared by loading automotive vehicle that are intermediate be- (charging) so that an air space is left in contact tween the wheels and the frame, and support with the explosive for the purpose of lessening the car body and frame by means of a cushion its shattering effect. { er sha¨t } of air to absorb road shock caused by passage Airslide conveyor [MECH ENG] An air-activated of the wheels over irregularities. { er sə¦spen gravity-type conveyor, of the Fuller Company, us- shən ¦sistəm } ing low-pressure air to aerate or fluidize pulver- air sweetening [CHEM ENG] A process in which ized material to a degree which will permit it to air or oxygen is used to oxidize lead mercaptides flow on a slight incline by the force of gravity. to disulfides instead of using elemental sulfur. { ¦erslı¯d kən¦va¯ər } { er swe¯təniŋ } air space [ENG] An enclosed space containing air system [MECH ENG] A mechanical refrigeraair in a wall for thermal insulation. { ¦er ¦spa¯s } tion system in which air serves as the refrigerant airspeed head [ENG] Any instrument or device, in a cycle comprising compressor, heat exusually a pitot tube, mounted on an aircraft for changer, expander, and refrigerating core. { er receiving the static and dynamic pressures of the sistəm } air used by the airspeed indicator. { erspe¯d air terminal [CIV ENG] A facility providing a hed } place of assembly and amenities for airline pasairspeed indicator [ENG] A device that com- sengers and space for administrative functions. putes and displays the speed of an aircraft rela- [ELEC] A structure, such as a tower, that serves tive to the air mass in which the aircraft is flying. as a lightning arrester. { er tərmənəl } { ¦erspe¯d indəka¯dər } air thermometer [ENG] A device that measures air spring [MECH ENG] A spring in which the the temperature of an enclosed space by means energy storage element is air confined in a con- of variations in the pressure or volume of air tainer that includes an elastomeric bellows or contained in a bulb placed in the space. { ¦er diaphragm. { er spriŋ } thə¦ma¨mədər } air-standard cycle [THERMO] A thermodynamic airtight [ENG] Not permitting the passage of air. cycle in which the working fluid is considered to Also known as airproof. { ertı¯t } be a perfect gas with such properties of air as a air-to-air resistance [CIV ENG] The resistance volume of 12.4 cubic feet per pound at 14.7 provided by the wall of a building to the flow of pounds per square inch (approximately 0.7756 heat. { ¦er tu¨ ¦er risistəns } cubic meter per kilogram at 101.36 kilopascals) air toxics See hazardous air pollutants. { er and 492R and a ratio of specific heats of 1:4. ¦ta¨ ksiks } { ¦er ¦standərd sı¯kəl } air trap [CIV ENG] A U-shaped pipe filled with air-standard engine [MECH ENG] A heat engine water that prevents the escape of foul air or gas operated in an air-standard cycle. { ¦er ¦stan from such systems as drains and sewers. See air dərd enjən } pocket. { er trap } air starting valve [MECH ENG] A device that air-tube breathing apparatus [ENG] A device admits compressed air to an air starter. { er consisting of a smoke helmet, mask, or mouth- ¦sta¨rdiŋ valv } piece supplied with fresh air by means of a flexiair stripping [CHEM ENG] The process of bub- ble tube. Also known as air-supply mask. { ¦er bling air through water to remove volatile or- tu¨ b bre¯thiŋ apə¦radəs } ganic substances from the water. { er stripiŋ } air-tube clutch [MECH ENG] A clutch fitted with air-supply mask See air-tube breathing apparatus. a tube whose inflation causes the clutch to en- { er sə¦plı¯ mask } gage, and deflation, to disengage. { er ¦tu¨ b air surveillance [ENG] Systematic observation kləch } of the airspace by visual, electronic, or other air valve [MECH ENG] A valve that automatically means, primarily for identifying all aircraft in that lets air out of or into a liquid-carrying pipe when airspace, and determining their movements. the internal pressure drops below atmospheric. { er sərva¯ləns } { er valv } air surveillance radar [ENG] Radar of moderate air vessel [ENG] 1. An enclosed volume of air range providing position of aircraft by azimuth which uses the compressibility of air to minimize and range data without elevation data; used for water hammer. Also known as accumulator. air-traffic control. { ¦er sər¦va¯ləns ¦rada¨r } 2. An enclosed chamber using the compressibilair survey See aerial survey. { ¦er ¦sərva¯ } ity of air to promote a more uniform flow of water air-suspension encapsulation [CHEM ENG] A in a piping system. { er vesəl } technique for microencapsulation of various air washer [MECH ENG] 1. A device for cooling types of solid particles; the particles undergo a and cleaning air in which the entering warm, 17
air-water jet hoist air is cooled below its dew point by refrig- thermometer that uses ethyl alcoho work- has less moisture per alidade ENG 1. An instrument for topographic ethod. 2. Any sighting device employed for air by passing the airstream through a liquid aligning parts during assembly. Iolin- leaning the surfaces of concrete or rock. Ier alignment ICV ENGI In a survey for a highway. tank in which the air above the water is com- ELECTR The process of adjusting components airway build a passage for ventilation be- ing the adjustment of tuned circuits for proper tween thermal insulation and roof boards airy points lENG! The points at which a hori:- (am m st rveying points along a straight line. air shaft ontal rod is optionally supported to avoid its plied to the measured length of a line to alld vertical plane the building, or shop permitting in its ids i Aitken dust counter er tengi am instrument for alignment wire See ground wire. Ia'tin-maont 'dast kaunt.ar all Aitken nucleus counter See Aitken dust counter. I at-kan'nu-kleas ated diode surfaces. I'al-ko, IT Tan'di, od alkaline wash CHEM ENGI The remo poses, by caustic soda solution. undesirable condition. (a'larm alarm valve ENG A device that sounds dec en water flows in an automatic sprinkler k o lEt 'bad-a that is, the paraffin with olefin Alberger process hich is thinner rest, especially the spandrel under uced and thus is separated from the Allen screw DES ENGA olt which alcoholmeter See alcoholometer. I, al-ko, ho"lim- has an axial hexagonal socket in its head. I'al straight or bent hexagonal rod, used to tum ch as a form alligator shears ENGI A cutting tool with a the quantity of an coholimeter; alcoholmeter. I al-k, hola ulcrum pin; used mainly for sh ons that do not require great accuracy. Ial alcohol thermometer ENG A liquid-in-glass
air-water jet moist air is cooled below its dew point by refrig- thermometer that uses ethyl alcohol as its workerated water so that although the air leaves close ing substance. { alkəho˙ l thərma¨mədər } to saturation with water, it has less moisture per alidade [ENG] 1. An instrument for topographic unit volume than when it entered. 2. Apparatus surveying and mapping by the plane-table to wash particulates and soluble impurities from method. 2. Any sighting device employed for air by passing the airstream through a liquid angular measurement. { aləda¯d } bath or spray. { er washər } aligning drift [MECH ENG] A rod or bar that is air-water jet [ENG] A jet of mixed air and water used for aligning parts during assembly. { əlı¯n which leaves a nozzle at high velocity; used in iŋ drift } cleaning the surfaces of concrete or rock. { alignment [CIV ENG] In a survey for a highway, ¦er ¦wo˙ dər jet } railroad, or similar installation, a ground plan air-water storage tank that shows the horizontal direction of the route. [ENG] A water storage [ELECTR] The process of adjusting components tank in which the air above the water is comof a system for proper interrelationship, includ- pressed. { ¦er ¦wo˙ dər sto˙rij taŋk } ing the adjustment of tuned circuits for proper airway [BUILD] A passage for ventilation be- frequency response and the time synchroniza- tween thermal insulation and roof boards. tion of the components of a system. [ENG] { erwa¯ } Placing of surveying points along a straight line. air well See air shaft. { er wel } { əlı¯nmənt } Airy points [ENG] The points at which a hori- alignment correction [ENG] A correction ap- zontal rod is optionally supported to avoid its plied to the measured length of a line to allow bending. { ¦ere¯ po˙ ins } for not holding the tape exactly in a vertical plane Airy stress function [MECH] A biharmonic func- of the line. { əlı¯nmənt kərekshən } tion of two variables whose second partial deriv- alignment pin [DES ENG] Pin in the center of atives give the stress components of a body sub- the base of an octal, loctal, or other tube having a ject to a plane strain. { ¦ere¯ stres fəŋkshən } single vertical projecting rib that aids in correctly aisleway [CIV ENG] A passage or walkway within inserting the tube in its socket. { əlı¯nmənt a factory, storage building, or shop permitting pin } the flow of inside traffic. { ı¯lwa¯ } alignment wire See ground wire. { əlı¯nmənt Aitken dust counter [ENG] An instrument for wı¯r } determining the dust content of the atmosphere. alkali ion diode [ENG] In testing for leaks, a de- Also known as Aitken nucleus counter. { ¦a¯tkən vice which senses the presence of halogen gases dəst kau˙ ntər } by the use of positive ions of alkali metal on the Aitken nucleus counter See Aitken dust counter. heated diode surfaces. { alkəlı¯ ı¯ən dı¯o¯ d } { ¦a¯tkən nu¨kle¯əs kau˙ ntər } alkaline wash [CHEM ENG] The removal of im- alarm gage [ENG] A device that actuates a sig- purities from kerosine,used for illuminating pur- nal either when the steam pressure in a boiler poses, by caustic soda solution. { alkəlı¯n is too high or when the water level in a boiler wa¨sh } is too low. { əla¨rm gaj } Alkar process [CHEM ENG] Catalytic alkylation alarm system [ENG] A system which operates of aromatic hydrocarbons with olefins to pro- a warning device after the occurrence of a dan- duce alkylaromatics; for example, production of gerous or undesirable condition. { əla¨rm ethylbenzene from benzene and ethylene. sistəm } { alkar pra¨səs } alarm valve [ENG] A device that sounds an alkylate bottom [CHEM ENG] Residue from fracalarm when water flows in an automatic sprinkler tionation of total alkylate which boils at a higher system. { əla¨rm valv } temperature than aviation gasolines. { al albedometer [ENG] An instrument used for the kəla¯t ba¨dəm } measurement of the reflecting power, that is, the alkylation [CHEM ENG] A refinery process for albedo, of a surface. { albəda¨mədər } chemically combining isoparaffin with olefin Alberger process [CHEM ENG] A method of hydrocarbons. { alkəla¯shən } manufacturing salt by heating brine at high pres- alle`ge [BUILD] A part of a wall which is thinner sure and passing it to a graveler which removes than the rest, especially the spandrel under a calcium sulfate; the salt crystallizes as the pres- window. { alezh } sure is reduced and thus is separated from the Allen screw [DES ENG] A screw or bolt which brine. { a¨lbərgər pra¨səs } has an axial hexagonal socket in its head. { al alcoholimeter See alcoholometer. { alkəho˙ lim ən skru¨ } ədər } Allen wrench [DES ENG] A wrench made from alcoholmeter See alcoholometer. { alkəho˙ l a straight or bent hexagonal rod, used to turn me¯dər } an Allen screw. { alən rench } alcoholometer [ENG] A device, such as a form alligator shears [ENG] A cutting tool with a of hydrometer, that measures the quantity of an fixed lower blade and a movable upper blade alcohol contained in a liquid. Also known as (shearing arm) that moves in an arc around a alcoholimeter; alcoholmeter. { alkəho˙ la¨ fulcrum pin; used mainly for shearing applicamədər } tions that do not require great accuracy. { al alcohol thermometer [ENG] A liquid-in-glass əga¯dər shirz } 18
altitude-azimuth mounting tor wrench DES ENG A wrench having alphatron See alpha-ray vacuum gage. Ial See altitude gn a portion of a re- alta allowable bearing value ICIv ENGI The maxi- for the simultaneous obse lat provides adequate safety against rupture of astronomical theodolite; universal instrument. ImpaIr nt- posing the pre g.I,altar nergy force other than fossil fuels that is used for construc- ond. Abbreviated ac. I allowable stress MECHI The maximum force r, nad-in safely applied to A or welding alternating stress fits. 3 la- ans nning or sliding forces wh force alternately acts in te directions standard hour. [a'la allowed time IND ENG Amount of time al altigraph ENGI A pressure altimeter that has recording mechanism to show the changes n work cycle. (a'laud'tit a fixed level. such impurity used. Also known as fused I'tim-ad- or I meter corrections ENG) Corrections which oy. resulting in a pn junction when the dis- altimeter setting ENG The value of own as fused-junction diode. ('a, loi lipnl nal system ICoNT SYSI A simp et(3 meters)above the tem in which there is no rotation of runway (approximately cockpit height). al he robot's body. I ol, tranz'la- shan al sis. altima indicate directly al 门如由知月ng1am onal weather limits. ['ol weth the atmosphere(altitude), generally by an altim- alpha ELECTRI The ratio between the chi ar urrent of a transistor. 'al-b j a I uch as averag orizon measured by an altitude -frequency value. alf ' kod, of a-ray vacuum gage ENG An ionizatio of byelectrons emitted from a hot filament: used efly for pressures fror om 10- to 10 torrs. Also telescope mounting in which the azimuth of the known as alphatron. ('al-fa, ra ' vak-yuim gai) direction in which the telescope is pointed is
altitude-azimuth mounting alligator wrench [DES ENG] A wrench having alphatron See alpha-ray vacuum gage. { al fixed jaws forming a V, with teeth on one or both fətra¨n } jaws. { aləga¯dər rench } alt See altitude. allocate [IND ENG] To assign a portion of a re- altazimuth [ENG] An instrument equipped with source to an activity. { alo¯ ka¯t } both horizontal and vertical graduated circles, allowable bearing value [CIV ENG] The maxi- for the simultaneous observation of horizontal mum permissible pressure on foundation soil and vertical directions or angles. Also known as that provides adequate safety against rupture of astronomical theodolite; universal instrument. the soil mass or movement of the foundation { altazəməth } of such magnitude as to impair the structure alt-azimuth mounting See altitude-azimuth mountimposing the pressure. Also known as allow- ing. { alt azəməth mau˙ ntiŋ } able soil pressure. { əlau˙əbəl beriŋ valyu¨ } alternate energy [ENG] Any source of energy allowable load [MECH] The maximum force other than fossil fuels that is used for constructhat may be safely applied to a solid, or is permit- tive purposes. { o˙ ltərnət enərje¯ } ted by applicable regulators. { əlau˙əbəl lo¯ d } alternating current [ELEC] Electric current that allowable soil pressure See allowable bearing reverses direction periodically, usually many value. { əlau˙əbəl so˙ il preshər } times per second. Abbreviated ac. { ¦o˙ l allowable stress [MECH] The maximum force tərna¯diŋ ¦kərənt } per unit area that may be safely applied to a alternating-current welder [ENG] A welding solid. { əlau˙əbəl stres } machine utilizing alternating current for welding allowance [DES ENG] An intentional difference purposes. { ¦o˙ ltərna¯diŋ ¦kərənt weldər } in sizes of two mating parts, allowing clearance alternating stress [MECH] A stress produced in usually for a film of oil, for running or sliding a material by forces which are such that each fits. { əlau˙əns } force alternately acts in opposite directions. allowed hours See standard hour. { əlau˙ d au˙ { o˙ ltərna¯diŋ stres } ərz } altigraph [ENG] A pressure altimeter that has a allowed time [IND ENG] Amount of time al- recording mechanism to show the changes in lowed each employee for personal needs during altitude. { altəgraf } a work cycle. { əlau˙ d tı¯m } altimeter [ENG] An instrument which deteralloy junction [ELECTR] A junction produced by mines the altitude of an object with respect to alloying one or more impurity metals to a semi- a fixed level, such as sea level; there are two conductor to form a p or n region, depending on common types: the aneroid altimeter and the the impurity used. Also known as fused junc- radio altimeter. { altimədər } tion. { alo˙ i jəŋkshən } altimeter corrections [ENG] Corrections which alloy-junction diode [ELECTR] A junction diode must be made to the readings of a pressure almade by placing a pill of doped alloying material timeter to obtain true altitudes; involve horizonon a semiconductor material and heating until tal pressure gradient error and air temperature the molten alloy melts a portion of the semicon- error. { altimədər kərekshənz } ductor, resulting in a pn junction when the dis- altimeter setting [ENG] The value of atmossolved semiconductor recrystallizes. Also pheric pressure to which the scale of an aneroid known as fused-junction diode. { alo˙ i ¦jəŋk altimeter is set; after United States practice, the shən dı¯o¯ d } pressure that will indicate airport elevation when all-translational system [CONT SYS] A simple the altimeter is 10 feet (3 meters) above the robotic system in which there is no rotation of runway (approximately cockpit height). { al the robot or its components during movements timədər sediŋ } of the robot’s body. { ¦o˙ l tranzla¯shənəl sis altimeter-setting indicator [ENG] A precision təm } aneroid barometer calibrated to indicate directly all-weather airport [CIV ENG] An airport with the local altimeter setting. { altimədər ¦sed facilities to permit the landing of qualified air- iŋ indəka¯dər } craft and aircrewmen without regard to opera- altimetry [ENG] The measurement of heights in tional weather limits. { o˙ l ¦wethər erpo˙rt } the atmosphere (altitude), generally by an altimalpha [ELECTR] The ratio between the change eter. { altimətre¯ } in collector current and the change in emitter altitude Abbreviated alt. [ENG] 1. Height, current of a transistor. { alfə } measured as distance along the extended earth’s alpha cutoff frequency [ELECTR] The frequency radius above a given datum, such as average at the high end of a transistor’s range at which sea level. 2. Angular displacement above the current amplification drops 3 decibels below its horizon measured by an altitude curve. { al low-frequency value. { alfə kədo˙ f fre¯kwən tətu¨ d } se¯ } altitude azimuth [ENG] An azimuth determined alpha-ray vacuum gage [ENG] An ionization by solution of the navigational triangle with altigage in which the ionization is produced by alpha tude, declination, and latitude given. { al particles emitted by a radioactive source, instead tətu¨ d azəməth } of by electrons emitted from a hot filament; used altitude-azimuth mounting [ENG] A two-axis chiefly for pressures from 10 telescope mounting in which the azimuth of the 3 to 10 torrs. Also known as alphatron. { alfə ra¯ vakyu¨ m ga¯j } direction in which the telescope is pointed is 19