HomeCalculatorsLube Oil TAN / Water - Condition Check

Lube Oil TAN / Water - Condition Check

Condition monitoring pass/fail for Total Acid Number (TAN) and water content against typical marine system-oil limits.

TANLubeCondition
Assessment
In-service

Formula, assumptions, and limits

Limits apply to 2-stroke system oil / 4-stroke crankcase oil. Water + TAN together indicate cylinder-cooling leak (high water) or overheated combustion (high TAN).

Symbol legend

SymbolMeaningUnitSource
Total Acid Numbermg KOH/gASTM D664
Free + emulsified water% v/vISO 3733 / Karl-Fischer