PAH Sensor enviroFlu-HC 500, enviroFlu-HC 5000, PAH Sensor enviroFlu-HC MB 500, enviroFlu-HC MB 5000

Common issues

• Optical window fouling/biofouling reducing sensor sensitivity and causing false low readings
• Calibration drift over time requiring periodic re-zeroing against a reference standard
• Air bubbles in the flow cell causing erratic or noisy readings
• Cable/connector corrosion at wet-space connections
• LED/light source degradation over long service life reducing signal strength
• Flow cell blockage from debris in the sample stream

Inspection checklist

• Inspect the optical window for fouling, scratching, or biofilm and clean per maker procedure
• Verify calibration against a known reference/check standard
• Check sample flow rate through the sensor's flow cell is within specification
• Inspect cable and connector for damage or corrosion
• Confirm sensor output correlates sensibly with recent discharge records
• Check power supply/signal cable integrity to the control/alarm unit
• Verify alarm setpoints match the applicable discharge limit for the equipment served
• Review the sensor's self-diagnostic/error log if provided

Service intervals

Critical spares

• Optical window/lens assembly
• Sensor cable/connector assembly
• Calibration reference standard/check solution
• O-rings/seals for the flow cell housing
• Complete replacement sensor head/probe, the typical service approach for this class of optical sensor when out of tolerance

Safety

• Normal hydrocarbon handling precautions apply, as the sensor is typically installed in an oily bilge water/hydrocarbon system
• Electrical hazard if serviced without isolating power
• A fouled or miscalibrated sensor can let an illegal discharge go undetected - correct function is environmentally as well as physically safety-critical

Class survey

Where fitted as part of Oil Discharge Monitoring Equipment (ODME) or an oily water separator 15 ppm alarm system, this sensor's type approval certificate and calibration record must be current and match the equipment fitted. Surveyors typically check the calibration log, alarm setpoint configuration, and that the unit is included in the vessel's IOPP Certificate supplement.