... are four models of DDS series Precision Conductivity Meters, Model DDS-11A, Model DDS-12A, Model DDS-307 and Model DDS-12D. Meters are suitable for ... brines or other concentrated solutions.Concise meter-panelLegible LCD displayerModel: DDS-12DConductivity Range: 0~2uS/cm, 2~20uS/cm, 20~200uS ...