movement caused by sloshing in the tank, a capacitor
is connected across the indicating meter to delay the
response (normally 3/4 second) of the meter to the
ALARM CONTROL SYSTEMS. Known as a
SENS-PAK alarm, its controls function integrally
with the tank level indication system to sense high,
low, or intermediate levels of tank liquids (as
appropriate) and actuates an alarm. The modular,
plug-in SENS-PAK units (fig. 4-47) are actuated by
transmitter. These units may or may not be included
in the primary receivers.
Although all primary receivers are prewired for
a maximum of two SENS-PAK units, normally used
for high and low level alarms, additional control units
may be incorporated in separate housings within the
same system on advice from the factory.
SENS-PAK alarm control adjustments are
located on the side of the receiver (refer to figure 4-46
[side panel]) and function as follows:
Normal simulate switchSubstitutes the float
simulator circuit for the transmitter in the indicating
meter circuit for alarm adjustment.
Float simulator potentiometerSimulates the to-
tal transmitter voltage divider resistance change over
the full range of float travel.
High alarm potentiometerSets the actuation
voltage level of the high alarm SENS PAK.
Low alarm potentiometerSets the actuation
voltage level of the low alarm SENS PAK.
This system surpasses the 3% accuracy
requirement of military specifications. But, the
accuracy will vary depending on the size tank being
gaged and the type receiver used.
The Gems TLI systems are also approved for
indicating the interface level of two liquids
having different specific gravities.
With the ON-OFF-FULL REF. toggle switch on
the primary receiver in the ON position, operation of
the system, and alarms if included, is completely
automatic. Tank liquid level is read directly from the
indicating meter on the primary or secondary
receiver as required. No further attention is
necessary, as the Gems TLI system can operate
indefinitely without any component degradation.
The only maintenance that should be required is
cleaning of the transmitter and float when tanks are
opened for inspection and cleaning.
The control console ushered in the modem era
for the ABF. It provides us with the ability to control
and monitor nearly all operations from one central
location. While the console relieves you of a lot of foot-
work, it requires an in-depth knowledge of your ships
systems and capabilities.
Each console (fig. 4-48) consists of a control panel
Figure 4-47.Primary receiver interior.