Total Chlorine Selection Guide: Portable Instruments Q-CL501 Portable Colorimeter for Free Chlorine, Chlorine Dioxide ( 5-para) Q-CL501B Free Chlorine &Total Chlorine&Combined Chlorine Portable Colorimeter T-6800 Multi-parameters Portable Colorimeter T-SP80 Pooltest Portable Colorimeter T-CP40 Portable Colorimeter for Drinking Water Lab Instruments Z-T700 Intelligent Multi-parameters Analyzer Z-D700 Multi-parameters Analyzer Online Analyzer K600 Water Online Analyzer(K-Y03)