How to judge the quality of RO membrane

There are many customers do not understand the film for the ro, is the choice of film, always distinguish the ro film is good or bad. Now I would like to introduce a simple bar.
Ro membrane is a water ion separation, water filtration, to the salt ions in water separation, and then through the water treatment equipment, respectively, the actual discharge. To remove impurities in water, the purpose of salt.
RO membrane pore diameter is one millionth of the hair (0.0001 microns), the general can not see the naked eye, bacteria, viruses, it is 5000 times, so only water molecules and some beneficial minerals through the human body, the other Impurities and heavy metals are discharged from the waste water pipe, all the desalination process, as well as astronauts wastewater treatment are used this method. Has been widely used in scientific research, medicine, food, beverages, desalination and other fields.
The film is good or bad, is that the effect of this filter. Is there really no way to get rid of impurities in the water, salt and so on.
1, look
Look at the membrane should be observed when the membrane is complete, whether fresh, because some external factors, may make ro film is not complete.
2, smell
Production and external factors, will make the film metamorphism, and some will issue a kind of strange smell, if the long-term storage properly, will make the ro film has a certain impact.
3, inspection
This is the best way to identify one of the ro film. The real production through the ro membrane out of the water, one without impurities, two no salt, three no minerals.
Ro film in the use of the process, from time to time to clean, in order to ensure the same water quality of water production, so ro film use more time.