ORP controller 2. Long-lasting test and controll the PH, ORP,conductivity and calcium data in the water. 3. LED ... 1. AC 120V-240V2. Long-lasting test and controll the PH, ORP,conductivity and calcium data in the water.3. Light ... -+1999mc0-1000mv±0.01mvPO-2310ph-orp controller ph:0-14ph orp:-1999mc-+1999mc ph:0-14ph orp:0-1000mvph:±0.01phorp:±0 ...