COULOMB'S LAW--Also called the LAW'
DIFFERENTIAL PRESSURE GAUGE--A
OF ELECTRIC CHARGES or the LAW OF
Bourdon-type gauge equipped with two Bourdon
tubes so arranged as to measure the difference in
ELECTROSTATIC ATTRACTION. Coulomb's
pressure between two pressure lines. Bellows
law states that charged bodies attract or repel each
gauges also measure differential pressure.
other with a force that is directly proportional to
the product of their individual charges and
inversely proportional to the square of the
DIFFUSER--A device that reduces the
distance between them.
velocity and increases the static pressure of a fluid
passing through a system.
CURRENT--The movement of electrons past
DIGITAL-- Pertaining to data in the form of
a reference point. The passage of electrons
through a conductor. It is measured in amperes.
DIGITAL SIGNAL--A signal in the form of
CYCLE--A complete cycle exists when the
a series of discrete quantities that have two distinct
voltage in an alternating current increases from
levels (for example, on/off).
zero to a maximum point, then decreases through
zero to a maximum point in the opposite direc-
DIGITAL TO ANALOG (D/A) CON-
tion, and returns to zero again.
VERSION--A conversion that produces an
analog output in the form of voltage or current
DAMAGE CONTROL CONSOLE (DCC)--
from a digital input.
This console is located in CCS and provides
monitoring for hazardous conditions (fire, high
DIRECT CURRENT (dc)--An electric cur-
bilge levels, and so forth). It also monitors the
rent that flows in one direction only.
ship's firemain and can control the fire pumps.
DISTILLATE-- The fresh water that is
DEADWEIGHT TESTER--A hydraulic
obtained from the distilling process.
balance-type gauge tester operating on the
principle of subjecting the gauge under test to a
DISTILLED WATER--Water that has been
hydrostatic pressure created by applying weights
to a piston of known area. The weighted piston
applies pressure to a fluid, such as oil, in the
cylinder, which in turn is transmitted to the gauge
EDUCTOR-- A mixing tube (jet pump) that
through a system of piping.
is used as a liquid pump to dewater bilges and
tanks. A GTM exhaust nozzle creates an eductor
DEAERATING FEED TANK (DFT)--A
effect to remove air from the enclosure.
device used in the waste-heat boiler (WHB) system
to remove dissolved oxygen and noncondensable
ELECTRIC PLANT CONTROL CONSOLE
gases from the feedwater.
(EPCC)-- This console contains the controls and
indicators used to remotely operate and monitor
DEAERATOR-- A device that removes air
from oil (for example, the lube oil storage and
conditioning assembly (LOSCA) tank which
separates air from the scavenge oil).
ELECTRIC PLANT CONTROL ELEC-
TRONICS ENCLOSURE (EPCEE)--The
DEMAND DISPLAY INDICATOR (DDI)--
EPCEE is a part of the EPCE. It contains power
A numerical display that is used to read values
supplies that provide the various operating voltage
of parameters within the engineering plant.
required by the EPCC on the DD and CG class
DENSITY--The quantity of matter contained
in a body.
ELECTRIC PLANT CONTROL EQUIP-
MENT (EPCE)--The EPCE provides centralized
remote control of the GTGS and electrical
DIFFERENTIAL PRESSURE--The differ-
distribution equipment. The EPCE includes the
ence between two pressures measured with respect
EPCC and EPCEE and is located in CCS.
to a common basis.