The Deckma OMD-11 manual lists four distinct alarm states. Understanding these saves hours of panic.
| Alarm Type | LCD Display | Likely Cause (per manual) | Action |
| :--- | :--- | :--- | :--- |
| Main Alarm | ALARM + High value | Real oil mist (piston blow-by, bearing hot spot) | Slow engine, investigate crankcase. |
| Pre-Alarm | PRE-ALARM | Rising mist or sensor drift | Increase monitoring, check scavenge fires. |
| Fault Alarm | FAULT + Code E-01 to E-12 | Electronic failure, no airflow, lens broken | Check blower motor, wiring, fuse F2. |
| Low Flow | FLOW ERROR | Blocked sampling tube, blower impeller stuck | Blow out tube with compressed air (careful: 0.5 bar max). |
Unlike older light-obscuration detectors, the OMD-11 uses a scattered light principle. The manual explains that the infrared LED sends a beam through the crankcase gas sample. If oil mist is present, light scatters onto a receiver diode. The manual’s optical diagrams are essential for understanding why condensation (not just oil) can trigger alarms.
A manual is only useful if the crew can apply it. Create a "One-Page Emergency Card" based on the manual’s Section 11: Emergency Bypass Procedure.
Drill Scenario: Crankcase oil mist alarm sounds during maneuver.
From the Manual:
Post this drill summary in the ECR. The full manual remains the reference for investigation (why did it alarm?).
The manual insists on a "Fresh Air Zero" test.
Deckma OMD-11 is a legacy bilge alarm unit designed to monitor oil-in-water concentrations in marine environments, specifically to ensure compliance with IMO Resolution MEPC.60(33) standards. Core Function & Features
The OMD-11 uses a light-scattering measurement principle to detect oil droplets in a sample stream. Key technical highlights from the Solids Suppression
: Designed to minimize false readings caused by non-oil contaminants like iron oxide, showing only 2 ppm for substances that older monitors might misread as 15 ppm. Dual Alarms deckma omd11 manual
: Features two independent alarm circuits factory-set to 15 ppm, though they are field-adjustable between 2 and 15 ppm via front-panel buttons. Output Signals
: Provides a 0(4)–20 mA signal for external recording or remote metering. Compact Build
: The unit is IP 65 rated for protection against water jets and dust, measuring approximately Technical Specifications Specification Measurement Range 0 – 30 ppm (Trend indication up to 50 ppm) plus or minus 5 ppm around the 15 ppm threshold per IMO standards Power Supply 24V AC/DC (standard); other voltages available on request Sample Temperature Operates between positive 1 raised to the composed with power 60 raised to the composed with power Response Time Adjustable alarm delays between 2 and 20 seconds Operational Guidelines Installation
: The unit should be mounted near the oily-water separator to minimize lag time. It requires a clean water source for flushing and mm OD piping for sample connections. Maintenance : Regular cleaning of the measuring cell is critical. The instruction manual
recommends using a dedicated cell cleaning brush and keeping spare desiccators and O-rings on hand. Calibration Check The Deckma OMD-11 manual lists four distinct alarm states
: Proper function is verified using a Formazin polymer reference standard (typically 4000 FTU diluted to specific requirements) to ensure the monitor remains within the required accuracy limits. Shivtech Marine Control Systems & Services calibration kit contents INSTRUCTION MANUAL DECKMA HAMBURG Gmbh - YUMPU
Here’s a helpful, practical review of the Deckma OMD-11 Oil Mist Detector Manual — based on common user feedback and technical documentation standards.
The manual details the two critical alarm thresholds:
Warning: The manual explicitly states that altering these thresholds without class approval voids your safety certification.