1.Today, water environment is the most basic environment for most laboratories, occupying a very important position in experiment. Water quality often determines the authenticity and repeatability of the results of many experiments. Most experts in laboratories usually require that concentration of impurity elements and chemical compounds in pure water are in ppb level or even lower. In the laboratory scientific research field, the starting point of purification that people focus on is tap water. If there is distilled water, deionized water or reverse osmosis water in laboratory, people will then only focus on the process of super purification.
在當今的實驗室中，水環境作為絕大多數實驗室的基本環境，在實驗中占的地位非常重要，水質往往決定了很多實驗結果的真實性、可重復性，對多數做實驗的專家來說，他們通常要求純水中的雜質元素和化臺物的濃度在ppb級甚至更低：在實驗室科學研究領域，所關心的純化起始點是自來水，如果實驗室中已有蒸餾水、去離子水或反滲透水，那就只注重超純化的過程。
Classification of pure water in laboratory / 實驗室純水的分級
Level III pure water: Physical purity of level III pure water is generally less than 50uS/cm. Distilled water, double distilled water (DDW), ordinary deionized water and reverse osmosis water all belong to this level. It is usually made through purification of tap water. Its main applications are in these fields, such as cleaning bottles and dishes, used for high pressure disinfection device, used in artificial environment and used in supply of ultra-pure water purifier.
Ⅲ級純水：Ⅲ級純水的物理純度一般為小于50uS/cm，單蒸水、雙蒸水、普通去離子水和反滲透水都屬于此級別。它一般由自來水純化制備而成。Ⅲ級純水的主要用途是清洗瓶皿，高壓消毒裝置用水，人工環境室用水廈超純水儀進水等。
Level II pure water: Level II pure water has a fuzzy range, often denoted by 5-15M-cm. But it does not necessarily strictly limit to this range. Ranging of 1-17M-cm can be considered as Level II pure water. It is made through ion exchange or electrodialysis of level III pure water. It’s mainly used in ordinary reagents compounding, ordinary chemistry experiment and water supply for ultra-pure water meter.
II級純水: II級純水是一個模糊的范圍，常用5-15M-cm表示。但II級純水絕不嚴格限于此范圍內，可以將1-17M-cm范圍均認為是II級純水。II級純水一般是將Ⅲ級純水再經過離子交換或電滲析而制成。主要用于般試劑的配制，普通化學實驗用水及給超純水儀供水。
Level I pure water: Level I pure water refers to water with physical purity more than 18M-cm, we usually take resistivity of 18.2M-cm as the index of level I pure water. Level I pure water must be made through re-purification of level II pure water or level III pure water by nuclear level ion exchange resin. It is mainly used in analysis experiments requiring high precision and life science experiment with high purity requirements for water.
I級超純水: I級超純水是指物理純度大于18M-cm的水，習慣稱電阻率為18.2M-cm是I級超純水的指標。級超純水一定是由Ⅲ級或Il級純水經核子級離子交換樹脂再純化而來。它主要用于高精密度的分析實驗和對水純度要求很高的生命科學實驗。
2.Laboratory pure water supply mode / 實驗室純水供應模式
Central pure water supply mode / 中央純水供應模式
Central pure water supply mode refers to setting pure water production device. Water for laboratory use is transported to each water demanding point through water supply pipelines, providing direct access to laboratory pure water or ultra pure water, whether it is a single laboratory or an experimental building.
中央純水供應模式是指設置純水生產裝置，實驗室用水通過供水管道輸送到各個實驗室用水點，無論是單個實驗室還是一幢實驗樓直接獲取實驗室純水或超純水。
Advantages 優點：
1. Lower running cost, centralized management.
運行成本低，管理集中。
2. Collective use, no possibility of machine standing idle.
集體使用，不存在機器閑置可能。
3. Large production, water is delivered by pipe network, many water supply points in one laboratory.
產量大，用水采用管網化，同一實驗室多點取水。
Disadvantages 缺點：
The system must ensure long-term safe operation, otherwise there will exist water-breaking risk.
系統必須保證長期安全運行，否則存在斷水風險。
Decentralized water supply mode / 分散純水供應模式
Decentralized water supply mode refers to setting water purification machine or purified water on each water supply point of laboratory.
分散純水供應模式是指在實驗室各用水點位置設置純水機或成品水。
Advantages 優點：
People have independent access to instruments, and instruments have high utilization ratio.
儀器有單獨的使用權，使用率高。
Disadvantages 缺點：
1. Operating cost is high, management is decentralized, and consumption cost is relatively higher.
運行成本高，管理分散，消耗成本相對較高。
2. Fixed-point installation on desk, fixed water supply points. Small production, low flow-rate and low efficiency.
桌面定點臺式安裝，定點取水，機型產量小，流量小，工作效率低。
3. If each experimental group purchases separately, then the total amount of investment on this product will be very high, and will result in vacancy rate increasing with the different working conditions of each experimental group, proving unfavorable for the maximization of investment efficiency.
若每個實驗組單獨購買，那么該類產品上的投資總額就會非常高，而且會隨著每個實驗組工作情況不同而導致空置率提高，不利于投資效率化。
With the development of laboratory equipment, pipe network and centralization of laboratory pure water supply have become the developing direction of large scale experimental buildings.
隨著實驗室裝備的發展，實驗室供水的管網化與集中化已成為大型實驗樓純水供應的發展方向。
3.Laboratory pure water supply mode / 實驗室純水供應模式
Central pure water supply mode / 中央純水供應模式
Central pure water supply mode refers to setting pure water production device. Water for laboratory use is transported to each water demanding point through water supply pipelines, providing direct access to laboratory pure water or ultra pure water, whether it is a single laboratory or an experimental building.
中央純水供應模式是指設置純水生產裝置，實驗室用水通過供水管道輸送到各個實驗室用水點，無論是單個實驗室還是一幢實驗樓直接獲取實驗室純水或超純水。
Advantages 優點：
1. Lower running cost, centralized management.
運行成本低，管理集中。
2. Collective use, no possibility of machine standing idle.
集體使用，不存在機器閑置可能。
3. Large production, water is delivered by pipe network, many water supply points in one laboratory.
產量大，用水采用管網化，同一實驗室多點取水。
Disadvantages 缺點：
The system must ensure long-term safe operation, otherwise there will exist water-breaking risk.
系統必須保證長期安全運行，否則存在斷水風險。
Decentralized water supply mode / 分散純水供應模式
Decentralized water supply mode refers to setting water purification machine or purified water on each water supply point of laboratory.
分散純水供應模式是指在實驗室各用水點位置設置純水機或成品水。
Advantages 優點：
People have independent access to instruments, and instruments have high utilization ratio.
儀器有單獨的使用權，使用率高。
Disadvantages 缺點：
1. Operating cost is high, management is decentralized, and consumption cost is relatively higher.
運行成本高，管理分散，消耗成本相對較高。
2. Fixed-point installation on desk, fixed water supply points. Small production, low flow-rate and low efficiency.
桌面定點臺式安裝，定點取水，機型產量小，流量小，工作效率低。
3. If each experimental group purchases separately, then the total amount of investment on this product will be very high, and will result in vacancy rate increasing with the different working conditions of each experimental group, proving unfavorable for the maximization of investment efficiency.
若每個實驗組單獨購買，那么該類產品上的投資總額就會非常高，而且會隨著每個實驗組工作情況不同而導致空置率提高，不利于投資效率化。
With the development of laboratory equipment, pipe network and centralization of laboratory pure water supply have become the developing direction of large scale experimental buildings.
隨著實驗室裝備的發展，實驗室供水的管網化與集中化已成為大型實驗樓純水供應的發展方向。