AVERAGE VALUE OF AC-- The average of all
ACID-- A solution that contains an excess of hydrogen
ions and exhibits a pH below the neutral value of 7.
the instantaneous values of one-half cycle of
ACTIVE-- A state in which a metal tends to corrode
(opposite to passive); freely corroding.
BASE-- A solution that contains an excess of hydroxyl
ions and exhibits a pH above the neutral value of 7.
AIR-CORE TRANSFORMER-- A transformer
composed of two or more coils, which are wound
BATTERY-- A device for converting chemical energy
around a nonmetallic core.
into electrical energy.
ALARM LOG-- A record of quantities that are in an
BATTERY CAPACITY-- The amount of energy
alarm condition only.
available from a battery. Battery capacity is
expressed in ampere-hours.
ALARM ACKNOWLEDGE-- A push button that
must be depressed to silence an alarm horn.
BELL LOG-- A printed record of changes in the ship's
operative conditions, such as speed or point of
AMMETER-- An instrument for measuring the
amount of electron flow in amperes.
AMPERE-- The basic unit of electrical current.
BINARY UNIT-- One of the two possible alternatives,
such as 1 or 0, YES or NO, ON or OFF.
ANALOG DATA-- Data represented in continuous
form, as contrasted with digital data having discrete
BLOCK DIAGRAM-- A drawing of a system using
blocks for components to show the relationship of
ANNUNCIATOR-- A device that gives an audible and
a visual indication of an alarm condition.
BURNISHING TOOL-- A tool used to clean and
polish contacts on a relay.
ANODE-- The positive electrode of an electro-
chemical device toward which the negative ions are
CARD-- See PRINTED CIRCUIT BOARD.
CASUALTY-- An event or series of events in progress
A N T I F O U L I N G -- The prevention of marine
during which equipment damage and/or personnel
organism attachment or growth on a submerged
injury has already occurred. The nature and speed
metal surface through chemical toxicity. Achieved
of these events are such that proper and correct
by the chemical composition of the metal, including
procedural steps will only serve to limit equipment
toxins in the coating, or by some other means of
damage and/or personnel injury.
distributing the toxin at the areas to be kept free of
CATHODE-- The general name for any negative
APPARENT POWER-- That power apparently
CATHODIC CORROSION-- Corrosion of a metal
available for use in an ac circuit containing a
reactive element. It is the product of effective
when it is a cathode. Occurs on metals, such as A1,
voltage times effective current expressed in
Zn, Pb, when the water solution turns strongly
voltamperes. It must be multiplied by the power
alkaline as a result of the normal cathodic reactions.
factor to obtain the true power available.
It is a secondary reaction between the alkali
generated and the amphoteric metal.
AQUEOUS-- A term pertaining to water; an aqueous
solution is a water solution.
CATHODIC POLARIZATION-- The change of the
electrode potential in the negative direction due to
ARMATURE-- In a relay, the movable portion of the