Generally, TDS ≤ 50 of RO ro RO pure equipment effluent is both direct drinking water and raw water. However, even if ro ro ro RO equipment is installed, TDS value is still high, so it is suspected that there is a problem with the quality of RO ro ro ro RO pure equipment. Generally, the higher the conductivity, the higher the salt content, the higher the TDS. The higher the TDS value, the more impurities are contained in the water. If TDS is high, it indicates that there are many impurities in water, and the quality of pure water is low, which can not meet the project requirements.

1、 TDS measurement method:

General end customers or dealers are used to directly detect TDS from tap water, which may lead to errors. The correct measurement method is to disconnect the pressure bucket and the rear position, and keep the machine in normal water making state for about 10 minutes (the water release time of the newly installed machine should be extended for about an hour), and then take water from the pure water outlet of the reverse osmosis membrane shell for water sampling. TDS detector has become one of the most commonly used water quality detection tools. Open the cover of TDS pen probe, press the on/ off button on the subscript, insert the TDS pen into the tested water after the LCD screen is displayed. After the value is stable, press the hold button on the subscript to read the value with TDS pen. After the test, wipe the TDS probe with dry paper.

TDS value of purified water reverse osmosis equipment reflects the content of dissolved substances in water, and the lower the value, the less the dissolved substances in water. TDS is measured in mg / L, that is, mg / L, which indicates how many grams of dissolved solids are contained in 1 litre of water. Among them, the soluble salts are calcium ions and magnesium ions; The ionic organic compounds ammonium acetate, sodium sulfate, etc; Some heavy metal ions are chromium, zinc, lead, copper, etc.

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2、 The reason that affects the TDS value is too high:

1. During the first water flow of RO membrane, there is a process of infiltration. During this period, a small amount of residual substances in membrane material production will be dissolved in water and washed out. If wet film is used, preservatives inside the membrane will also be dissolved in water and washed out. This process generally takes 1-2 hours, and TDS with pure water is gradually reduced.

2. A small amount of carbon powder and inorganic minerals in the later activated carbon will be washed out during the first water supply, which causes the TDS to be high. The solution is to fill the pressure bucket with water for the first time, and then switch the pure water tap several times repeatedly to make the impurities in the activated carbon filter element clean by pure water. The process is about an hour.

3、 Solution to high TDS value

In China, especially in the north, TDS is generally high, and the national municipal water is about 250, while in some areas, the TDS value of tap water and river lake water is up to 5600, and individual groundwater reaches thousands. If TDS value of source water is too high, it is recommended to add a pre protection before RO pure water equipment is used.

At the same time, for the problems that TDS value of RO ro RO pure water equipment cannot be reduced, the following aspects also need to be inspected:

(1) First, TDS value of raw water is checked, and the desalination rate of RO membrane is 90%;

(2) If it is a new replacement RO membrane, it needs to run for 20 minutes before measurement;

(3) Confirm whether the storage time of purified water in the water storage tank is too long;

(4) If the carbon is replaced, the washing is also needed;

(5) When measuring pure water quality, please measure from the pure water inlet of reverse osmosis membrane;

(6) After the above reasons are eliminated, RO ro ro RO membrane can be replaced.