Determination of chlorine in water sample

- May 22, 2018-

Manual chlorine level in tap water testing

Using chlorine test strips. The easiest method of testing the chlorine levels of your tap water at home is to use test strips. Chlorine test strips are similar in principle and manner of use to almost all other test strips like those used for urine or drug testing. It’s as simple as getting a sample of your tap water, dipping the strip as indicated in the instruction, waiting several seconds for the indicator-color to appear, and comparing such color to the chart provided for the level reading.

Test strips are advantageous because they are cheap, widely available on the market, and could give you instant results. The only disadvantage is the accuracy level. The best test strips on the market have accuracy ranges from 80%-90%.

Using chlorine test solutions. Chlorine test kits are also available in the liquid or solution form. The testing solution is sold in tiny dropper bottles similar to eye drops. Using the test solution is also straightforward. Collect tap water which will serve as the sample, add the number of drops indicated in the instruction, and finally compare the resulting color to the table or chart located on the label. The solution’s chemical composition reacts with chlorine, thus, changing the color of the water.

Using DPD chlorine testing tablets. The most basic method is to use DPD chlorine testing tablets. In fact, the two methods above are essentially a DPD method. DPD stands for diethyl-p-phenylene diamine, the chemical compound which reacts with chlorine and changes the color of the sample water. The manner of using DPD testing tablets is similar to the liquid solutions mentioned above. Get a sample tap water, mix in the tablet, and compare the color results on the test chart. What makes it a little more complicated is that there are four DPD tablet variants which test different variations of chlorines. DPD1 is intended for residual or free chlorine, DPD2 for monochloramine, DPD3 for combined chlorine, and DPD4 for total chlorine.

Using a gadget or device to test your tap water on chlorine levels

There are devices and equipment which can precisely measure chlorine levels in the water. But the only gadget available on the market for consumer or household use is the colorimeter. There are now handheld or portable colorimeter sold on certain shops and of course, on the internet.

With a colorimeter, there’s no longer a need for you to wait for the water’s changing color and assess what level does that color belong. With this gadget, it can give you the precise chlorine level in decimal numbers. The drawback? It’s a little more expensive than the manual test kits.