SpecificationModelHM-20PRM-20PHM-21PRangepH:0.00~14.00ORP:0~+/-1999mVpH:0.00~14.00ORP:0~+/-1999mVRepeatability+/-0.02pH+/-2mVpH:+/-0.02pHORP:+/-2mVCalibrationUpto3points.....Upto3pointsforpHTemperaterRange0~99 CTemperatureRepeatability+/-0.2 CDataStorage300dataPower