23-08: See the Light – Recent Advances in Fluorescence Help Take Control of Your Cooling Chemistry

Monitoring and control of cooling water treatment chemistry has evolved considerably through the years.  Benchtop wet chemical analysis of individual grab samples followed by manual adjustment of chemical metering pump output has been widely practiced since the 1960’s and is still in use today.  Many improvements to the manual process have evolved over the years including metering pumps with feedback capabilities, equipment that automates the sampling process and performs wet chemical analysis, and methods that involve the incorporation of fluorophores in the treatment chemistry.  Fluorescence has advantages over wet chemistry in that fluorophores can be detected at much lower levels and can be measured with robust solid-state probes placed in the cooling water flow without the need for reagents.  Early fluorophore applications, although well received commercially, had limitations.  Specifically, the fluorophore was initially applied only as an inactive tracer added to the finished product, and the sensing fluorometers struggled with accuracy in “dirty” waters.  This paper will discuss the recent advances in fluorescence that make it a compelling method, including incorporating the fluorophore into key active ingredients and significant improvements to fluorometer design.