I've been reading "A History of Beer and Brewing" by Hornsey, and he talks about the refinement of the hydrometer. One of the early hydrometers was a glass bubble and the user would attach weights to the bottom to allow measurements at different ranges.
This got me to thinking about my modern precision hydrometer, which goes from 0.999 to 1.071. When I need to measure something above that range, I use my less precise hydrometer that goes from 0.990 to 1.170.
I could just buy the higher range precision hydrometer...or I could make one for free with a metal washer. Using a wort sample of 1.065, I found a washer which will lower that to 1.018, effectively extending the range to 1.118, which covers all of the beers I've made.
Seems simple enough. Does anyone see a potential error in doing this?