AND Ion BM [BM-22] Microbalance, 22 x  0.01 mg - 25 mm Ø with Internal Calibration. The A&D Weighing BM-22 Ion BM Series Microbalance, 5.1/22g x 0.001/0.01mg 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.