I have two solutions to my gravity + floor + hydrometer issues after they claimed four in quick succession. Glued my hydrometer jar to a 12" squ piece of plywood and built a nice foam lined wooden box for it. Measure, take it out and put it straight back in the box, otherwise I turn around and knock it over.... or my two year old does the job for me!
Clem
That's basically what I have always done. It came in a clear plastic case with the instructions and I use it, rinse it off, dry with a towel, and right back into the case.