The SEKO Photometer System is a professional instrument for measuring chlorine, based on sampling with the photometric method (DPD). Real-time measurement of parameters ensures the highest accuracy in professional water-treatment applications. The Photometer System allows users to monitor up to six parameters: three parameters with the photometric sampling method and three parameters using external probes. Models available Single parameter Free chlorine Total chlorine Multi parameter: Free chlorine and pH Free chlorine, pH and ORP pH, ORP and free, total & combined chlorine