Water Testing. Some recommendations for choosing a method based on the sampling goals are detailed below:Project Evaluation: If your goal is to determine if users are adding the correct amount of chlorine and using the chlorine solution in the home, spot-checks in the home to sample the household water with a color-wheel kit provide more information than the pool test kits (free chlorine), while remaining relatively inexpensive and easy to use.If you have questions about chlorine residual testing, please contact To receive email updates about this page, enter your email address:Centers for Disease Control and Prevention. The color wheels are simpler and less expensive than digital meters because to measure the intensity of the color change, the field worker uses a color wheel to visually match the color to a numerical free or total chlorine reading. This approach is very useful for program monitoring because the presence of free chlorine in stored water obtained from an unchlorinated source is an objective measure that people are using the hypochlorite solution.There are three main methods to test free chlorine residual in drinking water in the field in developing countries: 1) Pool test kits, 2) Color-wheel test kits, and 3) Digital colorimeters. The range of the meter is 0 – 4 mg/L, equivalent to 0 – 4 ppm (parts per million).Selecting how to measure free and total chlorine can be complicated and is dependent on a number of factors in a program, including the need for accuracy, cost, and number of samples to be tested. It is vitally important that water is sampled and preserved correctly in order to ensure analysis results accurately reflect the in situ parameters (analytes and physical water properties) that you are trying to measure and base decisions on. It is a problem with buried objects, objects recovered from the sea, and metals han The Mohr method for determination of chloride in water is a pH sophisticated method. It is also known as Argentometric method. The levels of chloride may vary in water wells depending on the type of rock the ground water moves through and how long the ground water is in contact with the rock and has the ability to dissolve minerals. Thus, the free chlorine concentration will be less than the concentration of chlorine initially added (Free chlorine = Total chlorine measurement – Combined chlorine measurement).The SWS Program recommends testing free chlorine in two circumstances:The goal of dosage testing is to determine how much chlorine (sodium hypochlorite solution) to add to water that will be used for drinking to maintain free chlorine in the water for the average time of storage of water in the household (typically 4-24 hours). These kits are sold in many stores as a way to test the concentration of total chlorine in swimming pool water. Thus, the free chlorine concentration will be equal to the concentration of chlorine initially added. Chloride analysis is widely used as a tool for estimating the cycles of concentration, such as in cooling tower applications. Chloride is a naturally occurring anion that is found in surface and groundwater sources like well, surface/ground water, sea water, and also found in rainwater and tap water as well. Taste thresholds for sodium chloride and calcium chloride in water are in the range 200–300 mg/litre (2). please help.What should be the calculation if the sample needs to be diluted?Enter your email address to receive notifications of new posts by email. Chlorinated drinking water and sodium-chloride water softeners often increase chloride levels in wastewater of a community. Water sample is titrating against standard AgNOWhen silver nitrate solution is gradually added into the flask, then silver ions react with chloride ions and forms silver chloride. water (g/litre) Sodium chloride 357 391 Potassium chloride 344 567 Calcium chloride 745 1590 Organoleptic properties The taste threshold of the chloride anion in water is dependent on the associated cation. It is better to carry out between the pH ranges 7-8. All three methods depend on a color change to identify the presence of chlorine, and a measurement of the intensity of that color to determine how much chlorine is present.The first option for testing uses a liquid chemical OTO (orthotolidine) that causes a color change to yellow in the presence of total chlorine.