APPENDIX I
GLOSSARY
AMPLITUDE-- The size of a signal as
ALARM ACKNOWLEDGE--A push button
measured from a reference line to a maximum
that must be depressed to silence an alarm horn.
value above or below the line. Generally used to
describe voltage, current, or power.
ALLOWANCE PARTS LIST (APL)--Repair
parts required for units having the equip-
ANALOG DATA--Data represented in
ment/component listed.
continuous form, as contrasted with digital data
having discrete values.
ALLOY--Any composition metal produced
by the mixing of two or more metals or elements.
ANALOG SIGNAL--A measurable quantity
that is continuously variable throughout a given
range and that is representative of a physical
ALLOYING--The procedure of adding
quantity.
elements other than those usually comprising a
metal or alloy to change its characteristics and
ANALOG TO DIGITAL (A/D) CON-
properties.
VERSION--A conversion that takes an analog
input in the form of electrical voltage or current
ALLOYING ELEMENTS--The elements
and produces a digital output.
added to nonferrous and ferrous metals and alloys
to change their characteristics and properties.
ANNULAR--In the form of or forming a
ring.
ALTERNATING CURRENT (ac)--An
electrical current that constantly changes
ANNUNCIATOR--A device that gives an
amplitude and changes polarity at regular
audible and a visual indication of an alarm
intervals.
condition.
ANTISEIZE COMPOUND--A silicon-based,
AMBIENT-- Surrounding
on
all
sides,
high-temperature lubricant applied to threaded
encompassing.
components to aid in their removal after they have
been subjected to rapid heating and cooling.
A M B I E N T PRESSURE/TEMPERA-
TURE--The surrounding pressure/temperature,
ASBESTOS-- A noncombustible, noncon-
such as the air pressure/temperature that
ductive, fiber-like mineral used as an insulating
surrounds a conductor in a compartment or a
material.
piece of equipment.
ASBESTOSIS-- Fibrosis of the lungs caused
AMMETER--An instrument for measuring
by inhalation of asbestos.
the amount of electron flow (in amperes).
ATMOSPHERE-- A unit of measure equal
to 14.696 psi or 29.92 inches of mercury
AMPERE (amp)--A unit of electrical current
(1 atmosphere = 14.696 psi).
or rate of flow of electrons. One volt across 1 ohm
of resistance causes a current flow of 1 ampere.
ATMOSPHERIC PRESSURE--The pressure
(Named after A. M. Ampere, a famous French
of air at sea level, approximately 14.7 psi.
physicist.)
AI-1
