S.G. (density) = mass / (divided by the) volume.
Whenever I was attempting to do a specific Gravity test I always found it to be rather fiddly to get very accurate measurements for the displacement volume, with all of those tiny attachment wires that do have tendency to give larger volume measurements for small objects, and then accurately measure the volume of the displacement water which includes all of the droplets sticking behind in the containment vessels.
Where ever possible, when it comes to coins, I just cheat by looking up whatever published data I can find relating to a particular coin.
Edited by sel_69l
07/27/2021 10:20 pm