Windows and/or various styles of sight glasses and sight tubes in oil pans have been used for many years for this kind of testing.
A sight tube can give a more solid view of how much liquid oil is really there, without struggling to see through a hurricane.
if one were to make up a sight tube, what size of tubing would be best, and what material would one use that wouldn't cloud or degrade over time ?
where would be the best place to install the sight tube ?
what type of fittings would be the best to use ?
