The selection of a laboratory ultrapure water machine mainly depends on the quality of the raw water Water consumption The quality of water used has been determined.

   There are three types of water quality for national laboratory standards: Grade one water, Grade Two water, and Grade Three water. However, most laboratories only need two types of water quality. The first is Grade three water, such as distilled water, which is used for cleaning glassware, etc. The second type is grade one water, which is mainly used for chemical analysis or precision instrument analysis such as liquid chromatography and atomic absorption. Customers should select the grade of the ultrapure water machine based on their actual water quality requirements. All ultrapure water machines that use tap water as the water source have two(Two water qualities)The water outlet, first, is pure water, that is, grade three water; The second is grade one water, namely ultrapure water(Strictly speaking, the resistance of grade one water is greater than10MΩ.cmThe resistance of ultrapure water is greater than18MΩ.cm). Most customers are not clear about their water quality requirements. Although the relevant national departments have various water quality standards, they do not have complete quantitative indicators for specific experimental projects or water used in instrument analysis. Often, they only find that the water quality does not meet the standards after purchasing the ultrapure water machine. Based on experience, the following can be followed3Here are some purchasing principles, and they should correspond accordingly.
　　
1Current source of water usage:If your current water usage is qualified, you can also inform us of the source of this pure water. Our technicians will recommend the corresponding specification and model based on this situation.
　　
2Experimental content:It is divided into inorganic experiments and organic experiments. For inorganic experiments, only a resistance greater than is required18MΩ.cmAs long as the water quality is good, organic experiments usually need to remove organic substances from the water, so except for the resistance being greater than18MΩ.cmIn addition, an indicator of total organic carbon is also required. If it is a biological experiment, the substances in the water need to be removed.
　　
3Types of instruments:Customers can choose ultrapure water machines based on the types of instruments they use. The resistance of water in the liquid phase is greater than18MΩ.cm; And organic matter should be removed; The water consumption for atomic absorption, atomic fluorescence and environmental monitoring instruments is greater than18MΩ.cmJust fine;PCRThe water used for life science instruments has a resistance greater than18MΩ.cmIn addition, it is also necessary to remove organic substances, etc.