Hanna Instruments Blog

Differentiating Between Total and Free Chlorine

Written by Hanna Instruments | Jun 3, 2020 2:09:55 PM

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 sanitizing 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

Hanna's Free Chlorine Test Kit HI38017 measures low and medium range (0.00-0.70ppm and 0.0-3.5ppm, respectively), however, some customers may be interested in measuring a slightly higher range of free chlorine. Hanna offers a Free Chlorine Portable Photometer HI96701 which measures a range of 0.00-5.00ppm free chlorine.

Total Chlorine

The NEW Total Chlorine Ultra High Range Checker HI771 measures a medium to high range 0 to 500ppm Hanna’s Total Chlorine Test Kit HI3831T measures low to medium range 0.0-3.5ppm.

To learn more about Hanna Instruments click here.

More Hanna Products that Measure Chlorine:

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

Chlorine Controllers

BL121 Swimming Pool & Spa Controller

BL122/BL123 pH/ORP Controller with Hanna Cloud Connectivity

Photometers

HI96738 Chlorine Dioxide Portable Photometer

HI96711 Free and Total Chlorine Portable Photometer

HI96710 pH, Free Chlorine, and Total Chlorine Portable Photometer

HI97771 Free and Total Chlorine (Ultra High Range) Portable Photometer

HI97710 pH, Free and Total Chlorine Photometer

HI97734 Free and Total Chlorine High Range Photometer

HI97711 Free and Total Chlorine Photometer

HI96104 pH, Free Chlorine and Total Chlorine, and Cyanuric Acid Portable Photometer

Benchtops

HI83414 EPA Compliant Benchtop Turbidity and Chlorine Meter

HI83326 Pool and Spa Photometer

Checkers

HI761 Ultra Low Range Total Chlorine Colorimeter - Checker® HC

HI701 Free Chlorine Colorimeter - Checker® HC

Chlorine Test Kits

HI38020 Free and Total Chlorine Low, Medium, and High Range Test Kit

HI3831F Free Chlorine Test Kit, Extended Range