There is an ongoing debate over which reading is more useful - saturation point vs actual content. It really comes down to application. In an engine, there should be very low traces of moisture as it should be boiled off as the engine is running. Any moisture that is detected by FTIR in a combustion engine should be treated as suspicious.
Most labs should have the facility to test for both saturation and content. But remember, the saturation point of an oil will change depending on the temperature, age and additives in the oil. The saturation point can be as high as 0.1% content (1000 ppm).