You said the TDS pen you look at this news to know.
Information taken from: CCTV International www.cctv.com May 18, 2006 10:49
Source: China Consumer News
A reporter's investigation has found that the use of water electrolyzers to make tap water black and green misleads consumers into thinking that there is something wrong with the tap water. A water electrolysis scam designed to market water purifiers has become notorious in some cities. This scam is now trending toward rural penetration. In recent times, the Baoding City Water Supply Company in Hebei Province has been receiving calls from rural residents in the city's Gaoyang and Anxin counties asking if there are any problems with their tap water. The authorities hope to use this newspaper to remind rural consumers to be wary of the electrolyzed water scam.
Industrial and commercial law enforcement officials told reporters that water electrolysis is a trick of unscrupulous traders. Its water electrolyzer has two sets of electrodes, each set of electrodes with iron and aluminum rods, do the experiment will be electrodes were put into the tap water and pure water, after powering up the tap water began to become mixed, discoloration, while the pure water did not change much. At this time, the liar to the audience to explain the colorful substances as "pesticides", "viruses", "heavy metals" and other harmful substances, in order to promote their water purifiers.
According to the water supply company water quality laboratory personnel, tap water in the calcium and magnesium ions are electrolytes, electrolysis instrument anode of the iron bar into the tap water, iron is electrolyzed to form iron hydroxide (gray), divalent iron ions (green), iron oxide (reddish-brown), iron oxide (black); pure water does not contain conductive calcium and magnesium ions, electrolysis does not take place, so the pure water does not change color. If you use mineral water, mineralized water or put a little salt to do experiments with pure water, water will still change color.
In addition, there are vendors with TDS meter to measure tap water and pure water, "TDS" is the English language, the meaning of total dissolved solids, that is, melted in the water of the total salts, so the "TDS" level does not represent the quality of water.
The reporter learned that, due to law enforcement market regulation and media exposure, in the city gradually infamous electrolytic water performers to remote counties and rural areas to transfer the scam, mainly to some elderly friends and less educated farmers to explain the use of people eager to seek health, the scam of the ability to recognize the situation of the low to promote their products. (Sun Jianjun Li Jian)