Common issues
- Antenna/horn fouling from cargo vapor condensation or product residue
- False echoes or signal loss from tank internal obstructions (ladders, heating coils)
- Process connection seal leakage at the tank penetration
- Electronics/junction box moisture ingress
- Calibration drift over time, especially after a change of cargo type
- Cable and connector corrosion in the cargo tank environment
Inspection checklist
- Visual inspection of antenna/horn for buildup or damage
- Process connection and gasket/seal leak check
- Zero/span check against an independent manual ullage reading
- Junction box and cable gland condition (IP/ex-rating integrity)
- Cross-check reading against an independent level indication
- Intrinsic safety barrier and certification check where the unit is hazardous-area rated
- High/high-high level alarm setpoint verification
Service intervals
| Calibration check against manual sounding | at each cargo survey or per the SMS schedule |
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| Full function/alarm test | per PMS, commonly every 6-12 months |
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| Antenna cleaning | condition-based, especially after cargoes prone to residue or vapor buildup |
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Typical intervals for this design class, not the manufacturer’s figures for your model. The manufacturer’s manual is binding.
Critical spares
- Process seal/gasket kit
- Cable gland set
- Electronics/junction box module, if the design is modular
Safety
- This gauge is part of the overflow/high-level alarm chain - an unverified reading is a direct cargo overflow risk
- Hazardous-area/intrinsically-safe wiring must not be compromised during maintenance
- Tank access for antenna inspection requires an enclosed-space entry permit
Class survey
Class and PSC check that the independent high-level alarm functions separately from the primary gauge, that the installed unit's TA certificate (TAA0000204) matches the nameplate, and that calibration records are retained on board.