4-66.1. TANK LEVEL INDICATION - RECEIVER - MAINTENANCE INSTRUCTIONS (Continued).
ADJUSTMENTS AND ALIGNMENTS
Adjustment and alignments for the TLI systems are performed during initial installation, when testing
procedures indicate that a control is out of adjustment, and whenever a meter is replaced or repair is made in
an alarm circuit in a receiver module or receiver panel. Adjustments and alignments consist of meter calibration
procedures (which include zero adjustment, full-scale deflection adjustment, and fluid level calibrations) and
When performing adjustment and alignment procedures in fluid
tanks that contain or have contained in-flammable or explosive
fluids, ground the tank and observe all precautions for a
Fluid level meters on the receiver modules and receiver panel of a TLI system have their calibration
marks made at the factory on the basis of data supplied by the installing activity or can be marked in by ship's
personnel during installation or during replacement for corrective maintenance purposes. The following
calibration instructions provide a means of calibrating the zero, full-scale deflection, and intermediate fluid level
markings on 4-1/2 inch square meters.
The instructions provided for the calibration procedures describe a procedure in which meter
calibrations are initially made in pencil on unmarked meter faces and then with a more permanent marking
Zero Adjustment. Before other calibration or adjustment procedures are performed, meters shall be
zero adjusted in accordance with the procedure below.
(a) To zero adjust a meter, using a screwdriver, adjust the ZERO adjustment screw on the front of
the meter to its mid-position (if meter has no O-mark) or to the setting that causes deflection to the O-mark (if
meter has one). If there is no O-mark, remove the four frame mounting screws securing the face frame and
glass to the