tds meter working principle

TDS meter working principle

Among people who are concerned about the health of drinking water most of them would have a basic understanding with the "TDS test pen". The "TDS test pen" is one of the most commonly used drinking water quality testing tools at the moment.

TDS is the abbreviation of total dissolved solids, translated into Chinese is: "Total dissolved solids", the measurement unit is milligrams per liter (mg/L), it gives number to how many milligrams of dissolved solids in 1 liter of water, which includes soluble salts (Nagnesium ion, calcium ion, etc.), ionic organic matter (sodium sulfate, ammonium acetate, etc.), some heavy metal ions (chromium, lead, zinc, copper, etc.). The TDS value tells the content of soluble substances in the water.When the lower the value, it turns out the less the content of soluble substances in the water.

tds meter working principle

Of course, the quality of water depends on many factors, and TDS water tester is just one of many water quality indicators. Qualified drinking water quality also needs to be tested including microbiological indicators (total colonies, heat-resistant coliforms), toxicological indicators (heavy metal ion concentration), sensory characteristics (color, smell, taste, visible objects) and other indicators. To complete this series of testing equipment, professional instruments such as gas chromatograph, high performance liquid chromatograph, infrared oil tester, ion chromatograph, etc. are also needed to complete a complete water quality test.

tds meter working principle

But this is not to say that the TDS test pen has no practical effect. The TDS test pen detects the "Total Dissolved Solids", which is usually one of the indicators used to test the quality of RO reverse osmosis effluent, focusing on the detection of pure water that can be directly consumed. The remarkable drop in the value indicates that the water quality has improved. The standard for direct drinking water promulgated by the World Health Organization is that the TDS value is less than 50; the EU is less than 70; the United States is less than 50. Therefore, the relatively low cost of the TDS test pen presents us a quantifiable data to show whether the drinking water is within a reasonable range visually.

In addition, we also recommend a few simple water quality testing methods that can be done by yourself. Let’s try it.

1.Test the residual chlorine water

Plant to use chlorine to perform primary disinfection of tap water to make it meet the national safety standards. The treatment promotes the production of residual chlorine in the water. To test the residual chlorine, we need to prepare a residual chlorine test agent, and then prepare two cups of 15ML water, one cup is the water purified by the RO membrane water filter, and one cup is ordinary tap water. By adding 2 drops of the residual chlorine test agent to the two cups of water which will result in color change. There is a residual chlorine color comparison card in the manual of the residual chlorine test agent. The corresponding position on the color card can be found according to the color of the water, therefore we can roughly know the residual chlorine content. It is another option to compare two cups of water, the darker color has a higher residual chlorine content.

2.Test the organic matter and bacteria in the water

tds meter working in a cup of water

Not only residual chlorine will affect water quality, but organic matter and heavy metals will also affect it. In order to detect these pollutions, we need to use a water electrolyzer. Similarly, we prepare two cups of water, one cup is reverse osmosis membrane purified water, the other cup is ordinary tap water, then we put the aluminum and iron rods of the water electrolyzer into the water, plug in the power supply, press the switch, and turn on 0.5-1 After a minute or so, disconnect the power supply. At this time, we will find that both of the color of the two cups of water has changed. And the lighter the color of the water, the better the water quality, and vice versa.

Drinking water safety is evidently the goal that everyone yearns for and pursues. Learning to recognize water can better protect your own drinking water health. It takes time to change the drinking water environment, but we can start with each small family and use a water purifier to protect the health of each family’s drinking water!