... TDS meter, EC meter, CF meter, ORP controller PH meter, digital ph meter, pen type ph meter, PH controller, PH monitor, TDS meter, EC meter, CF meter, condutometer ... ± 0.01pH Orp: ± 0.01mv CDC400 conductivity meter 0-199.9ms ± 0.1ms CDC401 conductivity controller 0-199.9ms 0-100ms ± 0 ... .1ms KCC500 calcium meter 100-600ppm ± 1ppm KCC501 ...