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
]

]
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 }

]
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

{ ¦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
¨

]
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
[

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

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-

¯
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
]

¯
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

¯
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
[

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

¨
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

]
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

]
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
[

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

˙
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
[

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

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
˙

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

]
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

˙
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

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

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

¯
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
]

[
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

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
¯

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
[

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

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
˙

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 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
[

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
¯

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

[
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
]

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

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

[
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

¯
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

¯
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
]

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
¨