Dictionary of Engineering P2

air-water jet
moist air is cooled below its dew point by refrig- thermometer that uses ethyl alcohol as its work-
ing substance. { alиkəho
˙
lthərma
¨
mиədиər}
erated water so that although the air leaves close
alidade
[
ENG
]
1.
An instrument for topographic
to saturation with water, it has less moisture per
surveying and mapping by the plane-table
unit volume than when it entered.
2.
Apparatus
method.
2.
Any sighting device employed for
to wash particulates and soluble impurities from
angular measurement. { alиəda
¯
d}
air by passing the airstream through a liquid
aligning drift
[
MECH ENG
]

A rod or bar that is
bath or spray. { er washиər}
used for aligning parts during assembly. { əlı
¯
nи
air-water jet
[
ENG
]
A jet of mixed air and water
iŋdrift }
which leaves a nozzle at high velocity; used in
alignment
[
CIV ENG
]
In a survey for a highway,
cleaning the surfaces of concrete or rock. { ¦er
railroad, or similar installation, a ground plan
¦wo
˙
dиər jet }
that shows the horizontal direction of the route.
air-water storage tank
[
ENG
]
A water storage
[
ELECTR

]
The process of adjusting components
tank in which the air above the water is com-
of a system for proper interrelationship, includ-
pressed. { ¦er ¦wo
˙
dиər sto
˙
rиij 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
]
{ erwa
¯
}
Placing of surveying points along a straight line.
air well
See air shaft. { er wel }
{ əlı
¯
nиmənt }

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. { ¦erиe
¯
po
˙
ins }
for not holding the tape exactly in a vertical plane
Airy stress function
[
MECH
]
A biharmonic func-
of the line. { əlı
¯
nиmənt kərekиshən}
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. { ¦erиe
¯
stres fəŋkиshən}
single vertical projecting rib that aids in correctly
aisleway
[
CIV ENG
]
A passage or walkway within
inserting the tube in its socket. { əlı
¯
nиmənt
a factory, storage building, or shop permitting
pin }
the flow of inside traffic. { ı
¯
lwa
¯
}
alignment wire
See ground wire. { əlı
¯
nиmənt
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
¯
tиkən
vice which senses the presence of halogen gases
dəst kau
˙
ntиər}
by the use of positive ions of alkali metal on the
Aitken nucleus counter
See Aitken dust counter.
heated diode surfaces. { alиkəlı
¯
ı
¯
иən dı
¯
o
¯
d}

{ ¦a
¯
tиkən nu
¨
иkle
¯
иəs kau
˙
ntиər}
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. { alиkəlı
¯
n
is too high or when the water level in a boiler
wa
¨
sh }
is too low. { əla
¨

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. { əla
¨
rm
ethylbenzene from benzene and ethylene.
sisиtəm}
{ alkar pra
¨
sиəs}
alarm valve
[
ENG
]
A device that sounds an
alkylate bottom
[
CHEM ENG

]
Residue from frac-
alarm when water flows in an automatic sprinkler
tionation of total alkylate which boils at a higher
system. { əla
¨
rm valv }
temperature than aviation gasolines. { alи
albedometer
[
ENG
]
An instrument used for the
kəla
¯
t ba
¨
dиəm}
measurement of the reflecting power, that is, the
alkylation
[
CHEM ENG
]
A refinery process for
albedo, of a surface. { alиbəda
¨
иmədиər}
chemically combining isoparaffin with olefin
Alberger process
[

CHEM ENG
]
A method of
hydrocarbons. { alиkəla
¯
иshən}
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. { alezh }
sure is reduced and thus is separated from the
Allen screw
[
DES ENG
]
A screw or bolt which
brine. { a
¨
lиbərиgər pra
¨
sиəs}
has an axial hexagonal socket in its head. { alи

alcoholimeter
See alcoholometer. { alиkəho
˙
limи
ən skru
¨
}
ədиər}
Allen wrench
[
DES ENG
]
A wrench made from
alcoholmeter
See alcoholometer. { alиkəho
˙
l
a straight or bent hexagonal rod, used to turn
me
¯
dиər}
an Allen screw. { alиən 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. { alиkəho
˙
la
¨
и
fulcrum pin; used mainly for shearing applica-
mədиər}
tions that do not require great accuracy. { alи
əga
¯
dиər shirz }
alcohol thermometer
[
ENG
]
A liquid-in-glass
18
altitude-azimuth mounting
alligator wrench
[
DES ENG
]
A wrench having
alphatron

See alpha-ray vacuum gage. { alи
fətra
¨
n}fixed jaws forming a V, with teeth on one or both
jaws. { alиəga
¯
dиər rench }
alt
See altitude.
altazimuth
[
ENG
]
An instrument equipped with
allocate
[
IND ENG
]
To assign a portion of a re-
source to an activity. { aиlo
¯
ka
¯
t } both horizontal and vertical graduated circles,
for the simultaneous observation of horizontal
allowable bearing value
[
CIV ENG
]
The maxi-

mum permissible pressure on foundation soil and vertical directions or angles. Also known as
astronomical theodolite; universal instrument.that provides adequate safety against rupture of
the soil mass or movement of the foundation { altazиəиməth }
alt-azimuth mounting
See altitude-azimuth mount-of such magnitude as to impair the structure
imposing the pressure. Also known as allow- ing. { alt azиəиməth mau
˙
ntиiŋ }
alternate energy
[
ENG
]
Any source of energyable soil pressure. { əlau
˙
иəиbəl berиiŋvalиyu
¨
}
allowable load
[
MECH
]
The maximum force other than fossil fuels that is used for construc-
tive purposes. { o
˙
lиtərиnət enиərиje
¯
}that may be safely applied to a solid, or is permit-
ted by applicable regulators. { əlau
˙
иəиbəl lo

¯
d}
alternating current
[
ELEC
]
Electric current that
reverses direction periodically, usually many
allowable soil pressure
See allowable bearing
value. { əlau
˙
иəиbəl so
˙
il preshиər } times per second. Abbreviated ac. { ¦o
˙
lи
tərna
¯
dиiŋ ¦kərиənt }
allowable stress
[
MECH
]
The maximum force
per unit area that may be safely applied to a
alternating-current welder
[
ENG
]

A welding
machine utilizing alternating current for weldingsolid. { əlau
˙
иəиbəl stres }
allowance
[
DES ENG
]
An intentional difference purposes. { ¦o
˙
lиtərna
¯
dиiŋ ¦kərиənt weldиər}
alternating stress
[
MECH
]
A stress produced inin sizes of two mating parts, allowing clearance
usually for a film of oil, for running or sliding a material by forces which are such that each
force alternately acts in opposite directions.fits. { əlau
˙
иəns }
allowed hours
See standard hour. { əlau
˙
d au
˙
и { o
˙
lиtərиna

¯
dиiŋstres }
altigraph
[
ENG
]
A pressure altimeter that has aərz }
allowed time
[
IND ENG
]
Amount of time al- recording mechanism to show the changes in
altitude. { alиtəgraf }lowed each employee for personal needs during
a work cycle. { əlau
˙
d tı
¯
m}
altimeter
[
ENG
]
An instrument which deter-
mines the altitude of an object with respect to
alloy junction
[
ELECTR
]
A junction produced by
alloying one or more impurity metals to a semi- a fixed level, such as sea level; there are two

common types: the aneroid altimeter and theconductor to form a p or n region, depending on
the impurity used. Also known as fused junc- radio altimeter. { altimиədиər}
altimeter corrections
[
ENG
]
Corrections whichtion. { alo
˙
i jəŋkиshən}
alloy-junction diode
[
ELECTR
]
A junction diode must be made to the readings of a pressure al-
timeter to obtain true altitudes; involve horizon-made by placing a pill of doped alloying material
on a semiconductor material and heating until tal pressure gradient error and air temperature
error. { altimиədиərkərekиshənz }the molten alloy melts a portion of the semicon-
ductor, resulting in a pn junction when the dis-
altimeter setting
[
ENG
]
The value of atmos-
pheric pressure to which the scale of an aneroidsolved semiconductor recrystallizes. Also
known as fused-junction diode. { alo
˙
i ¦jəŋkи altimeter is set; after United States practice, the
pressure that will indicate airport elevation whenshən dı
¯
o

¯
d}
all-translational system
[
CONT SYS
]
A simple the altimeter is 10 feet (3 meters) above the
runway (approximately cockpit height). { alrobotic system in which there is no rotation of
the robot or its components during movements timиədиər sedиiŋ }
altimeter-setting indicator
[
ENG
]
A precisionof the robot’s body. { ¦o
˙
l tranzla
¯
иshənиəl sisи
təm } aneroid barometer calibrated to indicate directly
the local altimeter setting. { altimиədиər ¦sedи
all-weather airport
[
CIV ENG
]
An airport with
facilities to permit the landing of qualified air- iŋinиdəka
¯
dиər}
altimetry
[

ENG
]
The measurement of heights incraft and aircrewmen without regard to opera-
tional weather limits. { o
˙
l ¦wethиər erpo
˙
rt } the atmosphere (altitude), generally by an altim-
eter. { altimиəиtre
¯
}
alpha
[
ELECTR
]
The ratio between the change
in collector current and the change in emitter
altitude
Abbreviated alt.
[
ENG
]
1.
Height,
measured as distance along the extended earth’scurrent of a transistor. { alиfə }
alpha cutoff frequency
[
ELECTR
]
The frequency radius above a given datum, such as average

sea level.
2.
Angular displacement above theat the high end of a transistor’s range at which
current amplification drops 3 decibels below its horizon measured by an altitude curve. { alи
tətu
¨
d}low-frequency value. { alиfəkədo
˙
f fre
¯
иkwənи
se
¯
}
altitude azimuth
[
ENG
]
An azimuth determined
by solution of the navigational triangle with alti-
alpha-ray vacuum gage
[
ENG
]
An ionization
gage in which the ionization is produced by alpha tude, declination, and latitude given. { alи
tətu
¨
d azиəиməth }particles emitted by a radioactive source, instead
of by electrons emitted from a hot filament; used

altitude-azimuth mounting
[
ENG
]
A two-axis
telescope mounting in which the azimuth of thechiefly for pressures from 10
Ϫ3
to 10 torrs. Also
known as alphatron. { alиfəra
¯
vakиyu
¨
m ga
¯
j } direction in which the telescope is pointed is
19
altitude chamber
determined by rotation about a vertical axis and of specified sizes established as a standard in
the United States. Also known as Briggs pipethe corresponding altitude is determined by ro-
tation about a horizontal axis; computer-con- thread. { əmerиəиkən stanиdərd pı
¯
p thred }
American standard screw thread
[
DES ENG
]
trolled motors must move the telescope in both
altitude and azimuth to compensate for the Screw thread whose dimensions conform to
those of a particular series of specified sizes es-earth’s rotation. Also known as alt-azimuth
mounting. { ¦alиtətu

¨
d azиəиməth mau
˙
ntиiŋ } tablished as a standard in the United States;
used for bolts, nuts, and machine screws.
altitude chamber
[
ENG
]
A chamber within
which the air pressure, temperature, and so on { əmerиəиkən stanиdərd skru
¨
thred }
American system drill
See churn drill. { əmerиəиcan be adjusted to simulate conditions at differ-
ent altitudes; used for experimentation and test- kən ¦sisиtəm dril }
American Table of Distances
[
ENG
]
Publisheding. { alиtətu
¨
d cha
¯
mиbər}
altitude curve
[
ENG
]
The arc of a vertical circle data concerning the safe storage of explosives

and ammunition. { əmerиəиkən ta
¯
иbəl əv disиbetween the horizon and a point on the celestial
sphere, measured upward from the horizon. tənsиəz}
ammeter
[
ENG
]
An instrument for measuring{ alиtətu
¨
d kərv}
altitude datum
[
ENG
]
The arbitrary level from the magnitude of electric current flow. Also
known as electric current meter. { ame
¯
dиər}which heights are reckoned. { alиtətu
¨
d dadи
əm}
ammonia absorption refrigerator
[
MECH ENG
]
An absorption-cycle refrigerator which uses am-
altitude difference
[
ENG

]
The difference be-
tween computed and observed altitudes, or be- monia as the circulating refrigerant. { əmo
¯
nи
yəəb¦sorpиshənrifrijиəra
¯
dиər}tween precomputed and sextant altitudes.
Also known as altitude intercept; intercept.
ammonia compressor
[
MECH ENG
]
A device
that decreases the volume of a quantity of gas-{ alиtətu
¨
d difиrəns }
altitude intercept
See altitude difference. { alи eous ammonia by the amplification of pressure;
used in refrigeration systems. { əmo
¯
nиyətətu
¨
d inиtərsept }
aluminize
[
ENG
]
To apply a film of aluminum kəmpresиər}
ammonia condenser

[
MECH ENG
]
A device into a material, such as glass. { əlu
¨
mиənı
¯
z}
AM
See amplitude modulation. an ammonia refrigerating system that raises the
pressure of the ammonia gas in the evaporating
A-mast
[
ENG
]
An A-shaped arrangement of up-
right poles for supporting a mechanism designed coil, conditions the ammonia, and delivers it to
the condensing system. { əmo
¯
nиyə kəndensиto lift heavy loads. { a
¯
mast }
ambient
[
ENG
]
Surrounding; especially, of or ər}
ammonia liquor
[
CHEM ENG

]
Water solution ofpertaining to the environment about a flying air-
craft or other body but undisturbed or unaffected ammonia, ammonium compounds, and impuri-
ties, obtained from destructive distillation of bi-by it, as in ambient air or ambient temperature.
{ amиbe
¯
иənt } tuminous coal. { əmo
¯
nиyəlikиər}
ammonia meter
[
ENG
]
A hydrometer designed
American basement
[
BUILD
]
A basement lo-
cated above ground level and containing the specifically to determine the density of aqueous
ammonia solutions. { əmo
¯
иnyəme
¯
dиər}building’s main entrance. { əmerиəиkən ba
¯
sи
mənt }
ammonia synthesis
[

CHEM ENG
]
Chemical
combination of nitrogen and hydrogen gases at
American bond
[
CIV ENG
]
A bond in which ev-
ery fifth, sixth, or seventh course of a wall con- high temperature and pressure in the presence
of a catalyst to form ammonia. { əmo
¯
nиyəsinиsists of headers and the other courses consist
of stretchers. Also known as common bond; thəиsəs}
ammonia valve
[
ENG
]
A valve that is resistantScotch bond. { əmerиəиkən ba
¨
nd }
American caisson
See box caisson. { əmerиəи to corrosion by ammonia. { əmo
¯
nиyəvalv }
ammonoxidation
See ammoxidation. { aиkən ka
¯
sa
¨

n}
American filter
See disk filter. { əmerиəиkən filи məna
¨
kиsəda
¯
иshən}
ammoxidation
[
CHEM ENG
]
A process in whichtər}
American melting point
[
CHEM ENG
]
A temper- mixtures of propylene, ammonia, and oxygen are
converted in the presence of a catalyst, with acry-ature 3ЊF (1.7ЊC) higher than the American Soci-
ety for Testing and Materials Method D87 paraf- lonitrile as the primary product. Also known as
ammonoxidation; oxyamination. { ama
¨
kиsəfin-wax melting point. { əmerиəиkən meltиiŋ
po
˙
int } da
¯
иshən}
amortize
[
IND ENG

]
To reduce gradually an obli-
American standard beam
[
CIV ENG
]
A type of I
beam made of hot-rolled structural steel. gation, such as a mortgage, by periodically pay-
ing a part of the principal as well as the interest.{ əmerиəиkən stanиdərd be
¯
m}
American standard channel
[
CIV ENG
]
AC- {amиərtı
¯
z}
amount limit
[
IND ENG
]
In a test for a fixedshaped structural member made of hot-rolled
structural steel. { əmerиəиkən stanиdərd quantity of work, the time required to complete
the work or the total amount of work that canchanиəl}
American standard pipe thread
[
DES ENG
]
be completed in an unlimited time. { əmau

˙
nt
limиət}Taper, straight, or dryseal pipe thread whose di-
mensions conform to those of a particular series
amp
See amperage; ampere. { amp }
20
analytical centrifugation
ampacity
[
ELEC
]
Current-carrying capacity in telemetry, those systems of modulation in which
each component frequency f of the transmittedamperes; used as a rating for power cables.
{ampasиədиe
¯
} intelligence produces a pair of sideband frequen-
cies at carrier frequency plus f and carrier minus
amperage
[
ELEC
]
The amount of electric cur-
rent in amperes. Abbreviated amp. { amи f.{amиplətu
¨
d majиəla
¯
иshən}
amylograph
[

ENG
]
An instrument used toprij }
ampere
[
ELEC
]
The unit of electric current in measure and record the viscosity of starch and
flour pastes and the temperature at which theythe rationalized meter-kilogram-second sys-
tem of units; defined in terms of the force gelatinize. { əmı
¯
lиəgraf }
analemma
[
CIV ENG
]
Any raised constructionof attraction between two parallel current-
carrying conductors. Abbreviated a; A; amp. which serves as a support or rest. { anи
əlemиə }{ ampir }
ampere-hour meter
[
ENG
]
A device that meas-
analog
[
ELECTR
]
1.
A physical variable which

remains similar to another variable insofar asures the total electric charge that passes a given
point during a given period of time. { ampir the proportional relationships are the same over
some specified range; for example, a tempera-¦au
˙
иər me
¯
dиər}
amperometric transducer
[
ENG
]
A transducer ture may be represented by a voltage which is
its analog.
2.
Pertaining to devices, data, cir-in which the concentration of a dissolved sub-
stance is determined from the electric current cuits, or systems that operate with variables
which are represented by continuously meas-produced between two electrodes immersed in
the test solution when one of the electrodes is ured voltages or other quantities. { anиəla
¨
g}
analog output
[
CONT SYS
]
Transducer output inkept at a selected electric potential with respect
to the solution. { ampirиə¦meиtrik tranzdu
¯
и which the amplitude is continuously propor-
tional to a function of the stimulus. { anиsər}
amphibious

[
MECH ENG
]
Said of vehicles or əla
¨
g au
˙
tpu
˙
t}
analog readout
[
ENG
]
A scale on a balance thatequipment designed to be operated or used on
either land or water. { amfibиe
¯
иəs } continuously indicates measurement values by
the position of an index mark, either a line or
amplification factor
[
ELECTR
]
In a vacuum tube,
the ratio of the incremental change in plate volt- a pointer, opposite a graduated scale which is
usually marked with numbers. { anиəla
¨
gage to a given small change in grid voltage, under
the conditions that the plate current and all re
¯

dau
˙
t}
analog signal
[
ELECTR
]
A nominally continu-other electrode voltages are held constant.
{ amиpləиfəka
¯
иshən fakиtər } ous electrical signal that varies in amplitude or
frequency in response to changes in sound, light,
amplification noise
[
ELECTR
]
Noise generated
in the vacuum tubes, transistors, or integrated heat, position, or pressure. { anиəla
¨
g sigиnəl}
analog switch
[
ELECTR
]
1.
A device that eithercircuits of an amplifier. { amиpləиfəka
¯
иshən
no
˙

iz } transmits an analog signal without distortion or
completely blocks it.
2.
Any solid-state device,
amplifier
[
ENG
]
A device capable of increasing
the magnitude or power level of a physical quan- with or without a driver, capable of bilaterally
switching voltages or current. { anиəla
¨
gtity, such as an electric current or a hydraulic
mechanical force, that is varying with time, with- swich }
analog-to-digital converter
[
ELECTR
]
A deviceout distorting the wave shape of the quantity.
{ amиpləfı
¯
иər } which translates continuous analog signals into
proportional discrete digital signals. { ¦anиəla
¨
g
amplifier-type meter
[
ENG
]
An electric meter

whose characteristics have been enhanced by tə ¦dijиətиəlkənvərdиər}
analog-to-frequency converter
[
ELECTR
]
Athe use of preamplification for the signal input
eventually used to actuate the meter. { amи converter in which an analog input in some form
other than frequency is converted to a propor-pləfı
¯
иər ¦tı
¯
p me
¯
dиər}
amplify
[
ENG ACOUS
]
To strengthen a signal by tional change in frequency. { ¦anиəla
¨
gtə ¦fre
¯
и
kwənиse
¯
kənvərdиər}increasing its amplitude or by raising its level.
{ amиpləfı
¯
}
analog voltage

[
ELECTR
]
A voltage that varies
in a continuous fashion in accordance with the
amplitude-frequency response
See frequency re-
sponse. { amиplətu
¨
d fre
¯
иkwənиse
¯
rispa
¨
ns } magnitude of a measured variable. { anиəla
¨
g
vo
¯
lиtij }
amplitude-modulated indicator
[
ENG
]
A gen-
eral class of radar indicators, in which the sweep
analytical aerotriangulation
[
ENG

]
Analytical
phototriangulation, performed with aerialof the electron beam is deflected vertically or
horizontally from a base line to indicate the exis- photographs. { anиəlidиəиkəl ¦erиo
¯
trı
¯
aŋиgyə
la
¯
иshən}tence of an echo from a target. Also known as
deflection-modulated indicator; intensity-mod-
analytical balance
[
ENG
]
A balance with a sen-
sitivity of 0.1–0.01 milligram. { anиəlidиəиkəlulated indicator. { amиplətu
¨
d ¦ma
¨
jиəla
¯
dиəd
¦inиdəka
¯
dиər} balиəns }
analytical centrifugation
[
ENG

]
Centrifugation
amplitude modulation
[
ELECTR
]
Abbreviated
AM.
1.
Modulation in which the aplitude of a following precipitation to separate solids from
solid-liquid suspensions; faster than filtration.wave is the characteristic varied in accordance
with the intelligence to be transmitted.
2.
In { anиəlidиəиkəl sentrifиəga
¯
иshən}
21
analytical nadir-point triangulation
analytical nadir-point triangulation
[
ENG
]
Rad- in place.
[
ENG
]
A device, such as a metal rod,
wire,or strap, for fixing one object to another,ial triangulation performed by computational
routines in which nadir points are utilized as such as specially formed metal connectors used
to fasten together timbers, masonry, or trusses.radial centers. { anиəlidиəиkəl ¦nədir ¦po

˙
int
trı
¯
aŋиgyəla
¯
иshən}
[
MECH ENG
]
1.
In steam plowing, a vehicle lo-
cated on the side of the field opposite that of
analytical orientation
[
ENG
]
The computational
steps required to determine tilt, direction of prin- the engine and maintaining the tension on the
endless wire by means of a pulley.
2.
A devicecipal line, flight height, angular elements, and
linear elements in preparing aerial photographs for a piping system that maintains the correct
position and direction of the pipes and controlsfor rectification. { anиəlidиəиkəl o
˙
rиe
¯
иənta
¯
и

shən } pipe movement occurring as a result of thermal
expansion. { aŋиkər}
analytical photogrammetry
[
ENG
]
A method of
photogrammetry in which solutions are obtained
anchorage
[
CIV ENG
]
1.
An area where a vessel
anchors or may anchor because of either suitabil-by mathematical methods. { anиəlidиəиkəl
fo
¯
dиəgramиəиtre
¯
} ity or designation. Also known as anchor sta-
tion.
2.
A device which anchors tendons to the
analytical photography
[
ENG
]
Photography, ei-
ther motion picture or still, accomplished to de- posttensioned concrete member.
3.

In preten-
sioning, a device used to anchor tendons tempo-termine (by qualitative, quantitative, or any
other means) whether a particular phenomenon rarily during the hardening of the concrete.
4.
See deadman. { aŋиkəиrij }does or does not occur. { anиəlidиəиkəlfəta
¨
gи
rəиfe
¯
}
anchorage deformation
[
CIV ENG
]
The shorten-
ing of tendons due to their modification or slip-
analytical phototriangulation
[
ENG
]
A phototri-
angulation procedure in which the spatial solu- page when the prestressing force is transferred
to the anchorage device. Also known as an-tion is obtained by computational routines.
{ anиəlidиəиkəl fo
¯
dиo
¯
trı
¯
aŋиgyəla

¯
иshən } chorage slip. { aŋиkəиrij de
¯
fo
˙
rma
¯
иshən}
anchorage slip
See anchorage deformation. { aŋи
analytical radar prediction
[
ENG
]
Prediction
based on proven formulas, power tables, or kəиrij slip }
anchorage zone
[
CIV ENG
]
1.
In posttensioning,graphs; considers surface height, structural and
terrain information, and criteria for radar reflecti- the region adjacent to the anchorage for the
tendon which is subjected to secondary stressesvity together with the aspect angle and range to
the target. { anиəlidиəиkəl ra
¯
da
¨
rprədikи as a result of the distribution of the prestressing
force.

2.
In pretensioning, the region in whichshən}
analytical radial triangulation
[
ENG
]
Radial tri- transfer bond stresses are developed. { aŋиkəи
rij zo
¯
n}angulation performed by computational rou-
tines. { anиəlidиəиkəl ra
¯
dиe
¯
иəl triaŋиgyəla
¯
и
anchor and collar
[
DES ENG
]
A door or gate
hinge whose socket is attached to an anchorshən}
analytical three-point resection radial triangula-
embedded in the masonry. { aŋиkər ən ka
¨
lиər}
anchor block
[
BUILD

]
A block of wood, replac-
tion
[
ENG
]
A method of computing the coor-
dinates of the ground principal points of over- ing a brick in a wall to provide a nailing or fasten-
ing surface.
[
CIV ENG
]
See deadman. { aŋиlapping aerial photographs by resecting on three
horizontal control points appearing in the over- kər bla
¨
k}
anchor bolt
[
CIV ENG
]
A bolt used with its headlap area. { anиəlidиəиkəl ¦thre
¯
¦po
˙
int re
¯
sekи
shən ra
¯
dиe

¯
иəl triaŋиgyəla
¯
иshən } embedded in masonry or concrete and its
threaded part protruding to hold a structure or
analytical ultracentrifuge
[
ENG
]
An ultracentri-
fuge that uses one of three optical systems machinery in place. Also known as anchor rod.
{ aŋиkər bo
¯
lt }(schlieren, Rayleigh, or absorption) for the accu-
rate determination of sedimentation velocity
anchor buoy
[
ENG
]
One of a series of buoys
marking the limits of an anchorage. { aŋиkəror equilibrium. { anиəlidиəиkəl ¦əlиtrə¦senиtrə
fyu
¨
j} bo
˙
i}
anchor charge
[
ENG
]

A procedure that allows
analytic mechanics
[
MECH
]
The application of
differential and integral calculus to classical several charges to be preloaded in a seismic shot
hole; the bottom charges are fired first, and the(nonquantum) mechanics. { anиəlidиik mi
kanиiks } upper charges are held down by anchors. { aŋи
kər cha
¨
rj }
analyzer
[
ENG
]
A multifunction test meter,
measuring volts, ohms, and amperes. Also
anchored bulkhead
[
CIV ENG
]
A bulkhead se-
cured to anchor piles. { aŋиkərd bəlkhed }known as set analyzer.
[
MECH ENG
]
The com-
ponent of an absorption refrigeration system
anchor log

[
CIV ENG
]
A log, beam, or concrete
block buried in the earth and used to hold a guywhere the mixture of water vapor and ammonia
vapor leaving the generator meets the relatively rope firmly. Also known as deadman; ground
anchor. { aŋиkər la
¨
g}cool solution of ammonia in water entering the
generator and loses some of its vapor content.
anchor nut
[
DES ENG
]
A nut in the form of a
tapped insert forced under steady pressure into{ anиəlı
¯
zиər}
anchor
[
CIV ENG
]
A device connecting a struc- a hole in sheet metal. { aŋиkər nət}
anchor pile
[
CIV ENG
]
A pile that is located onture to a heavy masonry or concrete object to a
metal plate or to the ground to hold the structure the land side of a bulkhead or pier and anchors it
22

angel echo
through such devices as rods, cables, and chains. springs; an example is the Dines anemometer.
{ ¦aиnəиməbı
¯
иəgraf }{ aŋиkər pı
¯
l}
anchor plate
[
CIV ENG
]
A metal or wooden plate
anemoclinometer
[
ENG
]
A type of instrument
which measures the inclination of the wind tofastened to or embedded in a support, such as
a floor, and used to hold a supporting cable the horizontal plane. { ¦aиnəmo
¯
иklə¦na
¨
mи
ədиər}firmly. { aŋиkər pla
¯
t}
anchor rod
See anchor bolt. { aŋиkər ra
¨
d}

anemogram
[
ENG
]
A record made by an
anemograph. { əne
¯
mиəgram }
anchor station
See anchorage. { aŋиkər sta
¯
и
shən}
anemograph
[
ENG
]
1.
An instrument which re-
cords wind velocities.
2.
A recording anemom-
anchor tower
[
CIV ENG
]
1.
A tower which is a
part of a crane staging or stiffleg derrick and eter. { əne
¯

mиəgraf }
anemometer
[
ENG
]
A device which measuresserves as an anchor.
2.
A tower that supports
and anchors an overhead transmission line. air speed. { anиəma
¨
mиədиər}
anemoscope
[
ENG
]
An instrument for indicat-{ aŋиkər tau
˙
иər}
anchor wall
See deadman. { aŋиkər wo
˙
l } ing the direction of the wind. { əne
¯
mиəsko
¯
p}
anemovane
[
ENG
]

A combined contact ane-
AND circuit
See AND gate. { and sərиkət}
AND gate
[
ELECTR
]
A circuit which has two or mometer and wind vane used in the Canadian
Meteorological Service. { ¦anиəиmo
¯
¦va
¯
n}more input-signal ports and which delivers an
output only if and when every input signal port is
aneroid
[
ENG
]
1.
Containing no liquid or using
no liquid.
2.
See aneroid barometer. { anиəsimultaneously energized. Also known as AND
circuit; passive AND gate. { and ga
¯
t} ro
˙
id }
aneroid altimeter
[

ENG
]
An altimeter con-
AND/NOR gate
[
ELECTR
]
A single logic element
whose operation is equivalent to that of two taining an aneroid barometer that actuates the
indicator. { anиəro
˙
id altimиədиər}AND gates with outputs feeding into a NOR gate.
{ ¦and ¦no
˙
r ga
¯
t}
aneroid barograph
[
ENG
]
An aneroid barome-
ter arranged so that the deflection of the aneroid
AND NOT gate
[
ELECTR
]
A coincidence circuit
that performs the logic operation AND NOT, capsule actuates a pen which graphs a record on
a rotating drum. Also known as aneroidograph;under which a result is true only if statement A

is true and statement B is not. Also known as barograph; barometrograph. { anиəro
˙
id barи
əgraf }A AND NOT B gate. { ¦and ¦na
¨
t ga
¯
t}
AND-OR circuit
[
ELECTR
]
Gating circuit that
aneroid barometer
[
ENG
]
A barometer which
utilizes an aneroid capsule. Also known as an-produces a prescribed output condition when
several possible combined input signals are ap- eroid. { anиəro
˙
id bəra
¨
mиədиər}
aneroid calorimeter
[
ENG
]
A calorimeter thatplied; exhibits the characteristics of the AND
gate and the OR gate. { ¦and ¦o

˙
r sərиkət } uses a metal of high thermal conductivity as a
heat reservoir. { anиəro
˙
id kalиərimиədиər}
AND-OR-INVERT gate
[
ELECTR
]
A logic circuit
with four inputs, a
1
, a
2
, b
1
, and b
2
, whose output
aneroid capsule
[
ENG
]
A thin, disk-shaped box
or capsule, usually metallic, partially evacuatedis 0 only if either a
1
and a
2
or b
1

and b
2
are 1.
Abbreviated A-O-I gate. { ¦and ¦o
˙
rinvərt ga
¯
t } and sealed, held extended by a spring, which
expands and contracts with changes in atmos-
Andrade’s creep law
[
MECH
]
A law which states
that creep exhibits a transient state in which pheric or gas pressure. Also known as bellows.
{ anиəro
˙
id kapиsəl}strain is proportional to the cube root of time
and then a steady state in which strain is propor-
aneroid diaphragm
[
ENG
]
A thin plate, usually
metal, covering the end of an aneroid capsuletional to time. { andra
¯
dz kre
¯
p lo
˙

}
Andrews’s curves
[
THERMO
]
A series of iso- and moving axially as the ambient gas pressure
increases or decreases. { anиəro
˙
id diиəfram }therms for carbon dioxide, showing the depen-
dence of pressure on volume at various tempera-
aneroid flowmeter
[
ENG
]
A mechanism to
measure fluid flow rate by pressure of the fluidtures. { andru
¨
z kərvz }
anechoic chamber
[
ENG
]
1.
A test room in against a bellows counterbalanced by a cali-
brated spring. { anиəro
˙
id flo
¯
me
¯

dиər}which all surfaces are lined with a sound-ab-
sorbing material to reduce reflections of sound
aneroid liquid-level meter
[
ENG
]
A mechanism
to measure fluid depth by pressure of the fluidto a minimum. Also known as dead room; free-
field room.
2.
A room completely lined with a against a bellows which in turn acts on a manom-
eter or signal transmitter. { anиəro
˙
id ¦likиwədmaterial that absorbs radio waves at a particular
frequency or over a range of frequencies; used ¦levиəl medиər}
aneroidograph
See aneroid barograph. { anиprincipally at microwave frequencies, such as for
measuring radar beam cross sections. { ¦anи əro
˙
idиəиgraf }
aneroid valve
[
MECH ENG
]
A valve actuated orə¦ko
¯
иik cha
¯
mиbər}
anelasticity

[
MECH
]
Deviation from a propor- controlled by an aneroid capsule. { anиəro
˙
id
valv }tional relationship between stress and strain.
{ ¦anиəиlas¦tisиədиe
¯
}
angel echo
[
ENG
]
A radar echo from a region
where there are no visible targets; may be caused
anemobiagraph
[
ENG
]
A recording pressure-
tube anemometer in which the wind scale of the by insects, birds, or refractive index variations
in the atmosphere. { a
¯
nиjəl ekиo
¯
}float manometer is linear through the use of
23
angle back-pressure valve
angle back-pressure valve

[
MECH ENG
]
A back- joint between two surfaces meeting at an angle
pressure valve with its outlet opening at right
of less than 180Њ.{aŋиgəl filиət}
angles to its inlet opening. { aŋиgəl bak
angle fishplates
[
CIV ENG
]
Plates which join the
preshиər valv }
rails and prevent the rail joint from sagging
angle bar
[
BUILD
]
An upright bar at the meeting
where heavy cars and locomotives are used.
of two faces of a polygonal window, bay window,
Also known as angle; angle bar. { aŋиgəl
or bow window. { aŋиgəl ba
¨
r}
fishpla
¯
ts }
angle bead
[

BUILD
]
A strip, usually of metal or
angle float
[
ENG
]
A trowel having two edge sur-
wood, set at the corner of a plaster wall to protect
faces bent at 90Њ; used to finish corners in freshly
the corner or serve as a guide to float the plaster
poured concrete and in plastering. { aŋиgəl
flush with it. { aŋиgəl be
¯
d}
flo
¯
t}
angle beam
[
ENG
]
Ultrasonic waves transmit-
angle gauge
[
CIV ENG
]
A template used to set
ted for the inspection of a metallic surface at an
or check angles in building construction. { aŋи

angle measured from the beam center line to a
gəl ga
¯
j}
normal to the test surface. { aŋиgəl be
¯
m}
angle gear
See angular gear. { aŋиgəl ge
¯
r}
angle blasting
[
ENG
]
Sandblasting, or the like,
angle globe valve
[
ENG
]
A globe valve having
at an angle of less that 90Њ.{aŋиgəl blastиiŋ }
an angular configuration that permits it to be
angle block
[
ENG
]
A small block of wood used
fitted at bends in pipework. { ¦aŋиgəl ¦glo
¯

b
to fasten adjacent pieces, usually at right angles,
¦valv }
or glued into the corner of a wooden frame to
angle hip tile
See arris hip tile. { aŋиgəl hip tı
¯
l}
stiffen it. Also known as glue block. { aŋи
angle iron
[
CIV ENG
]
1.
An L-shaped cleat or
gəl bla
¨
k}
brace.
2.
A length of steel having a cross sec-
angle board
[
DES ENG
]
A board whose surface
tion resembling the letter L. { aŋиgəl ı
¯
иərn }
is cut at a desired angle; serves as a guide for

angle joint
[
ENG
]
A joint between two pieces of
cutting or planing other boards at the same
lumber which results in a change in direction.
angle. { aŋиgəl bo
˙
rd }
{ aŋиgəl jo
˙
int }
angle bond
[
CIV ENG
]
A tie used to bond ma-
angle lacing
[
CIV ENG
]
A system of lacing in
sonry work at wall corners. { aŋиgəl ba
¨
nd }
which angle irons are used in place of bars.
angle brace
[
ENG

]
A brace across the interior
{ aŋиgəl la
¯
sиiŋ }
angle of two members that meet at an angle.
angle method of adjustment
[
ENG
]
A method
Also known as angle tie. { aŋиgəl bra
¯
s}
of adjustment of observations which determines
angle brick
[
ENG
]
Any brick having an oblique
corrections to observed angles. { aŋиgəl
shape to fit an oblique, salient corner. { aŋи
methиəd əv əjəsиmənt }
gəl brik }
angle of action
[
MECH ENG
]
The angle of revo-
angle clip

[
CIV ENG
]
A short strip of angle iron
lution of either of two wheels in gear during
used to secure structural elements at right
which any particular tooth remains in contact.
angles. { aŋиgəl klip }
{ aŋиgəl əv akиshən}
angle closer
[
ENG
]
A specially shaped brick
angle of advance
See angular advance. { aŋиgəl
used to close the bond at the corner of a wall.
əv ədvans }
{ aŋиgəl klo
¯
zиər}
angle of approach
[
CIV ENG
]
The maximum
angle collar
[
DES ENG
]

A cast-iron pipe fitting
angle of an incline onto which a vehicle can move
which has a socket at each end for joining with
from a horizontal plane without interference.
the spigot ends of two pipes that are not in
[
MECH ENG
]
The angle that is turned through
alignment. { aŋиgəl ka
¨
lиər}
by either of paired wheels in gear from the first
angle-control section
See crossover. { aŋиgəl
contact between a pair of teeth until the pitch
kən¦tro
¯
l sekиshən}
points of these teeth fall together. { aŋиgəl
angle divider
[
DES ENG
]
A square for setting or
əv əpro
¯
ch }
bisecting angles; one side is an adjustable
angle of bite

See angle of nip. { aŋиgəl əv bı
¯
t}
hinged blade. { aŋиgəldəvı
¯
dиər}
angle of departure
[
CIV ENG
]
The maximum
angle dozer
[
MECH ENG
]
A power-operated ma-
angle of an incline from which a vehicle can move
chine fitted with a blade, adjustable in height
onto a horizontal plane without interference,
and angle, for pushing, sidecasting, and spread-
such as from rear bumpers.
[
ELECTR
]
See
ing loose excavated material as for opencast pits,
angle of radiation. { aŋиgəl əvdipa
¨
rиchər}
clearing land, or leveling runways. Also known

angle of depression
[
ENG
]
The angle in a verti-
as angling dozer. { aŋиgəldo
¯
zиər}
cal plane between the horizontal and a descend-
angle equation
[
ENG
]
A condition equation
ing line. Also known as depression angle; de-
which expresses the relationship between the
scending vertical angle; minus angle. { aŋиgəl
sum of the measured angles of a closed figure
əvdipreshиən}
and the theoretical value of that sum, the un-
angle of elevation
[
ENG
]
The angle in a vertical
knowns being the corrections to the observed
plane between the local horizontal and an as-
directions or angles, depending on which are
cending line, as from an observer to an object;
used in the adjustment. Also known as triangle

used in astronomy, surveying, and so on. Also
equation. { aŋиgəlikwa
¯
иzhən}
known as ascending vertical angle; elevation
angle fillet
[
ENG
]
A wooden strip, triangular in
cross section, which is used to cover the internal angle. { aŋиgəl əv elиəva
¯
иshən}
24
angular advance
angle of external friction
[
ENG
]
The angle be-
angle paddle
[
ENG
]
A hand tool used to finish
a plastered surface. { aŋиgəl padиəl}tween the abscissa and the tangent of the curve
representing the relationship of shearing resist-
angle plate
[
DES ENG

]
An L-shaped plate or a
plate having an angular section. { aŋиgəl pla
¯
t}ance to normal stress acting between soil and
the surface of another material. Also known as
angle post
[
BUILD
]
A railing support used at a
landing or other break in the stairs. { aŋиgəlangle of wall friction. { aŋиgəl əvekstərnиəl
frikиshən} po
¯
st }
angle press
[
MECH ENG
]
A hydraulic plastics-
angle of fall
[
MECH
]
The vertical angle at the
level point, between the line of fall and the base molding press with both horizontal and vertical
rams; used to produce complex moldings withof the trajectory. { aŋиgəl əv fo
˙
l}
angle of impact

[
MECH
]
The acute angle be- deep undercuts. { aŋиgəl press }
angle rafter
[
BUILD
]
A rafter, such as a hip rafter,tween the tangent to the trajectory at the point
of impact of a projectile and the plane tangent at the angle of the roof. { aŋиgəl rafиtər}
angle section
[
CIV ENG
]
A structural steel mem-to the surface of the ground or target at the point
of impact. { aŋиgəl əv impakt } ber having an L-shaped cross section. { aŋиgəl
sekиshən}
angle of nip
[
MECH ENG
]
The largest angle that
will just grip a lump between the jaws, rolls, or
angle-stem thermometer
[
ENG
]
A device used
to measure temperatures in oil-custody tanks;mantle and ring of a crusher. Also known as
angle of bite; nip. { aŋиgəl əv nip } the angle of the calibrated stem may be 90Њ or

greater to the sensitive portion of the thermome-
angle of obliquity
See angle of pressure. { aŋиgəl
əvo
¯
blikиwədиe
¯
} ter, as needed to fit the tank shell contour.
{ aŋиgəl ¦stem thərma
¨
mиədиər}
angle of orientation
[
MECH
]
Of a projectile in
flight, the angle between the plane determined
angle stile
[
BUILD
]
A narrow strip of wood used
to conceal the joint between a wall and a verticalby the axis of the projectile and the tangent
to the trajectory (direction of motion), and the wood surface which makes an angle with the
wall, as at the edge of a corner cabinet. { aŋиvertical plane including the tangent to the trajec-
tory. { aŋиgəl əv o
˙
rиe
¯
иənta

¯
иshən} gəl stı
¯
l}
angle structure
[
CIV ENG
]
A method of building
angle of pressure
[
DES ENG
]
The angle be-
tween the profile of a gear tooth and a radial a tower for mechanical strength in which braces
are placed at angles with respect to the verticalline at its pitch point. Also known as angle of
obliquity. { aŋиgəl əv preshиər } support rods. { aŋиgəl strəkиchər}
angle strut
[
CIV ENG
]
An angle-shaped struc-
angle of recess
[
MECH ENG
]
The angle that is
turned through by either of two wheels in gear, tural member which is designed to carry a com-
pression load. { aŋиgəl strət}from the coincidence of the pitch points of a pair
of teeth until the last point of contact of the

angle valve
[
DES ENG
]
A manually operated
valve with its outlet opening oriented at rightteeth. { aŋиgəl əv re
¯
ses }
angle of repose
[
ENG
]
See angle of rest. angles to its inlet opening; used for regulating
the flow of a fluid in a pipe. { aŋиgəl valv }
[
MECH
]
The angle between the horizontal and
the plane of contact between two bodies when
angle variable
[
MECH
]
The dynamical variable
w conjugate to the action variable J, defined onlythe upper body is just about to slide over the
lower. Also known as angle of friction. { aŋи for periodic motion. { aŋиgəl verиe
¯
иəиbəl}
angling dozer
See angle dozer. { aŋиgliŋdo

¯
zиər}gəl əvripo
¯
z}
angle of rest
[
ENG
]
The maximum slope at
angstrom
[
MECH
]
A unit of length, 10
Ϫ10
meter,
used primarily to express wavelengths of opticalwhich a heap of any loose or fragmented solid
material will stand without sliding, or will come spectra. Abbreviated A; A
˚
. Also known as
tenthmeter. { aŋиstrəm}to rest when poured or dumped in a pile or on
a slope. Also known as angle of repose. { aŋи
A
˚
ngstro
¨
m compensation pyrheliometer
[
ENG
]

A pyrheliometer consisting of two identical Man-gəl əv rest }
angle of thread
[
DES ENG
]
The angle occurring ganin strips, one shaded, the other exposed to
sunlight; an electrical current is passed throughbetween the sides of a screw thread, measured
in an axial plane. { aŋиgəl əv thred } the shaded strip to raise its temperature to that
of the exposed strip, and the electric power re-
angle of torsion
[
MECH
]
The angle through
which a part of an object such as a shaft or wire quired to accomplish this is a measure of the
solar radiation. { o
˙
ŋиstrəmka
¨
mиpənsa
¯
иshənis rotated from its normal position when a torque
is applied. Also known as angle of twist. { aŋи ¦pı
¯
rhe
¯
le
¯
a
¨

mиədиər}
angular acceleration
[
MECH
]
The time rate ofgəl əv to
˙
rиshən}
angle of twist
See angle of torsion. { aŋиgəl əvchange of angular velocity. { aŋиgyəиlərakselи
əra
¯
иshən}twist }
angle of wall friction
See angle of external friction.
angular accelerometer
[
ENG
]
An accelerome-
ter that measures the rate of change of angular{ aŋиgəl əv ¦wo
˙
l frikиshən}
angle of wrap
[
DES ENG
]
On a band brake velocity between two objects under observation.
{ aŋиgyəиlərakselиəra
¨

mиədиər}mechanism, the distance, expressed in degrees,
that the brake band wraps around the brake
angular advance
[
MECH ENG
]
The amount by
which the angle between the crank of a steamflange. { aŋиgəl əv rap }
25