N3000-DMP10, -DMP20, -DMP30, -DMP31, -DSP10, -DSP20, -SSP01

Common issues

• Signal loss or erratic readings from antenna fouling (product buildup, condensation) in the tank
• False high/low readings from foam, turbulence or vapour interface effects in the cargo
• Cable or connector corrosion at the tank penetration or junction box
• Calibration drift over time versus manual ullage/sounding checks
• Communication faults between the gauge and the cargo control/IGS system
• Antenna or stilling well damage during tank cleaning or cargo operations

Inspection checklist

• Cross-check the gauge reading against manual ullage/sounding at the start of cargo operations
• Visual inspection of the antenna/stilling well for damage or fouling where accessible (tank entry/dry-dock)
• Check cable glands, junction boxes and penetrations for corrosion or water ingress in the hazardous-area installation
• Verify calibration/zero and span against a known reference per the maker's procedure
• Check alarm setpoints (high level, high-high level) against the cargo/ballast operations manual
• Confirm intrinsic safety barriers and certification documentation are in place
• Test the communication link to the cargo control system / IGS displays

Service intervals

Typical intervals for this design class, not the manufacturer’s figures for your model. The manufacturer’s manual is binding.

Typical wear limits

Ranges are typical for this design class. Always confirm against the manufacturer documentation for your serial number.

Critical spares

• Radar transmitter/sensor head unit
• Antenna assembly
• Intrinsically safe barrier/interface module
• Display/processing unit
• Cable glands and connectors rated for the hazardous area

Safety

• Gauge is installed in a hazardous cargo tank environment - maintenance must preserve intrinsic safety/explosion-protection certification, with no unauthorised substitution of components
• Tank entry for antenna inspection requires full enclosed-space entry procedures (gas-free certificate, permit)
• Loss of reliable level indication is a safety-critical failure for overfill prevention - a back-up sounding procedure must be in place if the gauge is unreliable

Class survey

Surveyor checks the cargo level gauging system as part of cargo control and overfill prevention arrangements, verifies calibration/cross-check records against manual sounding, and confirms hazardous-area (Ex) certification documentation for the tank-mounted sensor and cabling (cert. TAA00000UZ).