Difference between free and total chlorine

Chlorine is a common chemical used by for disinfection. High levels of chlorine, whether in liquid or produced by electrolysis of salt, is used in a variety of industries including produce washing, food processing, and the disinfection of medical equipment due to its’ effectiveness as a biocide.

Hanna Instruments prides itself on its ability to help customers easily and accurately measure commonly required elements essential to their field including total and free chlorine.

It is important to note the difference between free and total chlorine.

Free chlorine refers to available forms of chlorine, such as Hypochlorous acid and Hypochlorite, which are added to solutions for disinfection. When free chlorine combines with contaminants, it becomes combined chlorine, otherwise known as chloramines. Once chlorine is combined, it has a decreased ability to disinfect.

The measure of total chlorine will always be higher than free chlorine, as it is the sum of both free chlorine and combined chlorine. Thus, measuring free chlorine is a direct indication of the effectiveness of sanitising solution.

Hanna Instruments offers a wide range of instrumentation for measuring chlorine. From Chemical Test Kits (CTK) and Checker Handheld Colorimeters to single and Multiparameter field meters and bench tops, Hanna has an accurate, affordable solution for nearly any free and total chlorine application.

Free Chlorine Portable Photometer

Free Chlorine Range 0.00 to 5.00mg/L (as Cl2). The HI97701 has an innovative optical system that offers superior performance in accuracy, repeatability, and the short amount of time it takes to perform a measurement.

Free & Ultra High Range Total Chlorine Portable Photometer

Free Chlorine Range 0.00 to 5.00mg/L (as Cl2) Total Chlorine Range 0 to 500mg/L (as Cl2)

HI97771 is an advanced portable photometer for the measurement of free and ultra-high range total chlorine in water. This meter offers a superior optical system that utilises a reference detector and narrow band interference filters for extremely fast and repeatable measurements

These products are for everyone: home pool owners, maintenance services, pool installation companies, public and private pools.

The range includes chlorine controllers, photometers, benchtops, checkers, & chlorine test kits.

HANNA INSTRUMENTS

JHB: (011) 615 6076 CPT: (011) 946 1722 DBN: (031) 701 2711 hanna@hanna.co.za www.hanna.co.za