McGraw-Hill Dictionary of Engineering Second Edition

potentiometric controllerpotentiometric controller [CONT SYS] A con- 7000 avoirdupois pound, or 0.3732417216 kilogram.troller that operates on the null balance princibreviatedAlso known as apothecaries’ pound (abtrollerple, in which an error signal is produced by balinlb ap in the United States or lb apothancing the sensor signal against a set-point voltlbthe United Kingdom); troy pound (abbreviatedage in the input circuit; the error signal ist in the United States, or lb tr or lb in theamplified for use in keeping the load at a desired United Kingdom). { pau˙ nd }temperature or other parameter. { pə¦tenchē poundal [MECH] A unit of force in the Britishə¦metrik kəntrōlər }absolute system of units equal to the forcepotentiostat [ENG] An automatic laboratory inpoundwhich will impart an acceleration of 1 ft/s 2 to astrument that controls the potential of a workingmass, or to 0.138254954376 newton.electrode to within certain limits during coulopoundal-foot{ pau˙ ndəl }See foot-poundal. { pau˙ ndəl fu˙ t}metric (electrochemical reaction) titrations.{pətenchēəstat }pound-foot See foot-pound. { pau˙ nd fu˙ t}pot furnace [ENG] 1. A furnace containing sevpoundmass See pound. { pau˙ nd mas }pound force See pound. { pau˙ nd fȯrs }eral pots in which glass is melted. 2. A furnacein which the charge is contained in a pot or pound per square foot [MECH] A unit of pres-crucible. { pät fərnəs }sure equal to the pressure resulting from a forcepothole [CIV ENG] A pot-shaped hole in a pave- of 1 pound applied uniformly over an area ofment surface. { päthōl }1 square foot. Abbreviated psf. { pau˙ nd pərPotier diagram [ELEC] Vector diagram showing¦skwer fu˙ t}pound per square inchthe voltage and current relations in an alternatsureequal to the pressure resulting from a force[MECH] A unit of pres-ing-current generator. { pōtyā dīəgram }of 1 pound applied uniformly over an area ofpot life [CHEM ENG] See work life. [ENG] The1 square inch. Abbreviated psi. { pau˙ nd pərperiod of time during which paint remains useful¦skwer inch }after its original package has been opened orpounds per square inch absolute [MECH] Theafter a catalyst or other additive has been incorabsolute,thermodynamic pressure, measured byporated. Also known as spreadable life; usablethe number of pounds-force exerted on an arealife. { pät līf }of 1 square inch. Abbreviated lbf in. 2 abs; psia.potometer [ENG] A device for measuring tran-{ pau˙ ns pər ¦skwer inch absəlüt }spiration, consisting of a small vessel containingpounds per square inch differential [ENG] Thewater and sealed so that the only escape of moisdifferencein pressure between two points in ature is by transpiration from a leaf, twig, or smallfluid-flow system, measured in pounds perplant with its cut end inserted in the water.square inch. Abbreviated psid. { pau˙ ns pər{pōtämədər }¦skwer inch difərenchəl }potomology [CIV ENG] The systematic study ofpounds per square inch gage [MECH] The gagethe factors affecting river channels to provide thepressure, measured by the number of poundsbasisfor predictions of the effects of proposed force exerted on an area of 1 square inch. Abengineeringworks on channel characteristics. breviated psig. { pau˙ ns pər ¦skwer inch gāj }{ pädəmäləjē } pour test [ENG] The chilling of a liquid underpot plunger [ENG] A plunger used to force soft- specified test conditions to determine the Amerienedplastic molding material into the closed can Society for Testing and Materials (ASTM)cavity of a transfer mold. { pät plənjər } pour point. { pȯr test }potter’s wheel [ENG] A revolving horizontal powder clutch [MECH ENG] A type of electrodiskthat turns when a treadle is operated; used magnetic disk clutch in which the space betweento shape clay by hand. { pädərz wēl } the clutch members is filled with dry, finely dipotting[ELECTR] Process of filling a complete vided magnetic particles; application of a magelectronicassembly with a thermosetting com- netic field coalesces the particles, creating fricpoundfor resistance to shock and vibration, and tion forces between clutch members. { pau˙ dfor exclusion of moisture and corrosive agents. ər kləch }{ pädiŋ } powder flowmeter [ENG] A device used topound [MECH] 1. A unit of mass in the English measure the flow rate of a metal powder.absolute system of units, equal to 0.45359237 { pau˙ dər flōmēdər }kilogram. Abbreviated lb. Also known as av- powder house [CIV ENG] A magazine for theoirdupois pound; pound mass. 2. A unit of temporary storage of explosives. { pau˙ dərforce in the English gravitational system of units, hau˙ s}equal to the gravitational force experienced by powder keg [ENG] A small metal keg for blacka pound mass when the acceleration of gravity blasting powder. { pau˙ dər keg }has its standard value of 9.80665 meters per sec- powder-moisture test [ENG] Determination ofond per second (approximately 32.1740 ft/s 2 ) moisture in a propellant by drying under preequalto 4.4482216152605 newtons. Abbrevi- scribed conditions; expressed as percentage byated lb. Also spelled Pound (Lb). Also known weight. { pau˙ dər mȯischər test }as pound force (lbf). 3. A unit of mass in the powder molding [ENG] Generic term for plastroyand apothecaries’ systems, equal to 12 troy tics-molding techniques to produce objects ofor apothecaries’ ounces, or 5760 grains, or 5760/ varying sizes and shapes by melting polyethylene418