DPD vs. Probe: Choosing The Right Online Technology For Free Chlorine, Total Chlorine, And Monochloramine

Ensuring effective disinfection is the cornerstone of safe drinking water, but selecting the right chlorine monitoring technology often involves a complex trade-off between accuracy and maintenance. While DPD colorimetric methods remain the gold standard for regulatory compliance and resistance to sample interferences, the ongoing costs of reagents and tubing maintenance can add up over time. Fortunately, advancements in amperometric probe technology offer a reagent-free alternative that provides real-time data with lower operational expenses. By understanding how factors like pH compensation, flow dependence, and sample matrix impact each method, utility operators can move beyond a "one size fits all" approach to find the most reliable and cost-effective solution for their specific process.