SENSOR-- A component that senses physical
variables and produces a signal to be observed or
MENT (RTE)--Same as RTD.
to actuate other elements in a control system.
Temperature, pressure, sound, and position
RESISTOR-- A device possessing the property
sensors are examples.
SEQUENCE VALVE--An automatic valve in
RHEOSTAT-- A variable resistor having one
a fluid power system that causes one actuation
fixed and one moveable terminal.
to follow another in definite order.
RPM AND PITCH INDICATOR UNIT
SEQUENTIALLY--In a predesigned se-
(RPIU)--This unit is mounted in the pilot house
quence, not necessarily in numerical order.
and is part of the SCE. It is identical to the
BWDU except that it also displays port and star-
SERIAL DATA BUS--A major communica-
board CRP propeller pitch on a DD or CG class
tion link between ship control equipment,
PAMCE, and PLOE. The bus is time-shared
between the consoles. Control and status
SCAVENGE PUMP--A pump used to
information is exchanged in the form of serial
remove oil from a sump and return it to the oil
data words on a DD or CG class ship.
SERVICE TANKS--The service tanks that
SCHEMATIC DIAGRAM--A diagram using
contain purified fuel from the storage tanks.
graphic symbols to show how a circuit functions
SET POINT--The numerical value of a
parameter at which an alarm is actuated.
SECURE--(1) To make fast or safe. (2) The
order given on completion of a drill or exercise.
SHELL INSERT BEARING--A bearing in
(3) The procedure followed with any piece of
which the wearing surface is installed on a thin
equipment that is to be shut down.
shell. This shell is removable from the bearing
SECURED PLANT CONFIGURATION
(MODE)-- The condition in which engines of a
SHIM-- A thin layer of metal or other
set are disengaged from the reduction gear/pro-
material used to true up a machine or inserted in
pulsion shaft on a DD or CG class ship.
bearings to permit adjustments after bearing wear.
SELECTOR SWITCH--Usually a rotary-type
SHIP CONTROL CONSOLE (SCC)--This
switch with more than two line connections. The
console is located on the bridge. It has equipment
selector switch permits the connection (by a jack
for operator control of ship's speed and direction.
outlet) of a permanently connected handset to any
other wired-in circuit. In some stations, where
SHIP CONTROL EQUIPMENT (SCE)--
only two circuits are involved, a double-throw
Bridge-located equipment of the ECSS, which
toggle switch is normally used.
includes SCC, SCEEE, PSCU, BWDU, and
RPIU on a DD or CG class ship.
SENSING ELEMENT OR SENSOR--The
part of an instrument that first takes energy from
SHIP CONTROL EQUIPMENT ELEC-
the measured medium to produce a condition
TRONICS ENCLOSURE (SCEEE)--The
representing the value of the measured variable.
SCEEE (located in CIC) is part of the SCE. It
has power supplies that provide the various
SENSING POINT--Physical and/or func-
operating voltages required for the SCC, BWDU,
tional point in a system at which a signal may be
and RPIU on a DD or CG class ship.
detected or monitored in an automatic operation.
SHIP'S SERVICE AIR SYSTEM (SSAS)--
This system supplies compressed air at 150 psig
SENSITIVITY--The smallest change in the
to a majority of the ship's pneumatically operated
value of a variable being measured to which the
instrument will respond.