Stir bars Magnetic stirrer

four magnetic stir bars meter stick.

a stir bar magnetic bar placed within liquid provides stirring action. stir bar s motion driven rotating magnet or assembly of electromagnets in stirrer device, beneath vessel containing liquid. stir bars typically coated in teflon, or less in glass. glass coatings used liquid alkali metals (except lye, eat through glass) , alkali metal solutions in ammonia. both coatings chemically inert , not contaminate or react reaction mixture in.

they bar shaped , octagonal in cross-section (sometimes circular), although variety of special shapes exist more efficient stirring. stir bars have ridge around center (called pivot ring) on rotate. smallest few millimeters long , largest few centimeters. stir bar retriever separate magnet on end of long stick (usually coated teflon) can used remove stir bars vessel.