Oil mist detector (OMD)

An oil-mist detector continuously samples crankcase atmosphere and trips an alarm and engine slowdown when oil-mist concentration rises toward the lower explosive limit, the early warning of a hot bearing or blow-by before it can cause a crankcase explosion. IACS UR M10 requires it on engines of 2250 kW and above or with cylinder bore over 300 mm. It complements, rather than replaces, the crankcase explosion relief valves of UR M9.