Inline Water Instruments Conductivity / TDS / Resistivity pH / ORP Free Chlorine / CLO2 Dissolved Oxygen Turbidity Fluorine Flow RO Program Controller Sensors / Accessories Portable Water Instruments Conductivity / TDS pH / ORP Dissolved Oxygen Thermometer Sensors / Accessories Basket Online Free Chlorine / CLO2 Controller POP-8300A Free Chlorine Meter Measurement range: 0.1-2mg/L or 0.1-20mg/L, Free chlorine probe / pH probe / temperature probe.