[Unclenick]

Bee215,

You remind me that most balance beam scales these days are magnetically damped. The magnet that the aluminum plate slides between can attract iron particles, filings, and rust dust. If you get enough it will drag mechanically on the plate and spoil the readings. You want to lift the scale off the knife edge and slip a cleaning patch into the magnet gap; possibly with a little mineral spirits on it to help it pick debris up. Mineral spirits will dry off, but don't put any kind of oil in there as attracting dust won't help matters.