Halogen MP5 More Accurate Than Hach CL10 – San Jose Water The Report Details Background San Jose Water (SJW) required an accurate, low-maintenance sensor for continuous chlorine monitoring. The existing equipment required constant calibration and maintenance, and it suffered deviation at low residual concentrations. Operators decided to trial the Halogen MP5™ against the Hach CLT-10. For the test, SJW deployed a Halogen MP5™ and a Hach CLT10 in a 2.37