Gauging Tape Plumb-Bobs

Plumb-Bobs are weighted devices used as a sinker on the end of a gauging tape. Most are made from brass or other non-sparking and chemically insensitive metals. As a general rule, heavy Bobs are for thick oils, while lighter ones can be used for thinner fluids.  In general, when selecting the weight, 20oz Bobs work well for almost every fluid environment. Lastly, blunt-nosed Bobs are preferred for thin fluids to minimize any possibility of the Bob chipping or denting the bottom of the tank.