AND Ion BM [BM-200] Analytical Balance, 220g x 0.1mg - 90mm Ø with Internal Calibration. The A&D Weighing BM-200 Ion BM Series Analytical Balance, 220g x 0.1mg features auto response adjustment allows balance to auto or manually stabilize FAST, MID, SLOW depending on draft & vibration influences. The BM20 auto self-calibration will detect changes in ambient temperature and auto calibrate.