We produce a total residual oxidant (TRO) sensor for ballast water monitoring and dechlorination. Our unique approach to multiparameter sensors allows us to measure total oxidants (chlorine/bromine) contained in water by using a three electrode amperometric method. This allows for the accurate measurement for Oxidation Reduction Potential (ORP), temperature, conductivity, Practical Salinity Unit (PSU) and pH. Our simple, robust, compact system is both ATEX/ IECEx certified. Non EX versions can be installed directly into the ballast pipe. The sensor: • Is flow independent up to 4.5 m/sec velocity • Requires no reagents, membranes or electrolyte • Will operate in seawater or freshwater • Is self-cleaning Over 2,000 sensors have been delivered since 2014. Our TRO sensor is protected by over 11 patents in the US, Korea, China and several more patents pending in the US and other countries.