真空泵在真空优先域的作用是从真空容器中抽出气体分子，降低真空容器内的气体压力，使之达到要求的真空度。随着真空行业的应用的迅速发展，很多厂商已经研制出很多种类的真空泵，其抽气速率从每秒零点几升到每秒几十万、数百万升。概括地讲从大气压力到极高真空度是一个很大的范围，至今为止还没有一种真空系统能覆盖这个范围。有时为达到不同产品的工艺指标、工作效率和设备工作寿命要求，不同的真空区段需要选择不同的真空系统配置。
医疗器械、仪器仪表优先域常常使用微型真空泵、气体采样泵，流量多在20L/min以下。微型真空气泵种类繁多，常见的有旋片式泵、柱塞泵、薄膜泵等。为达到比较好的配置，选择微型真空气泵时，应考虑以下各点：
1、确定工作真空范围。每一个行业都有其适应的真空度范围，必须确定该行业所要求的真空度。对于气体采样泵而言，若是采集的气体本身有一定负压，那么真空度参数也必须考虑。
2、确定极限真空度。在确定了行业要求的真空度的基础上检查真空泵系统的极限真空度，因为极限真空度决定了真空泵的工作真空度。一般来讲，系统的极限真空度比系统的工作真空度低20%，比前级泵的极限真空度低50%。仪器常用的微型真空气泵一般真空度可以达到10kPa。
3、确定抽气的种类、性质与抽气量。如果输送高温、腐蚀性的气体需要特制的隔膜泵。各款微型真空泵的结构原理不同，有的微型真空泵需要使用润滑、密封液体，可能与输送的气体发生反应，有的则可能产生磨损，还得考虑被抽气体的污染问题。微型隔膜泵运动机构与输送介质完全隔离，具有不污染介质，无泄漏的突出优点，但抽气量不如旋片式真空泵。
综上，微型泵、采样泵的性价比。泵的价格与性能密切相关。生产高真空度、大流量、可靠性好、寿命长的微型泵，需要厂家具有先进的流体技术和丰富的经验、优质的材料、高精度的机械加工和装配，还要经过长期的实验、严格的检验挑选。过高的技术指标会导致泵的成本大幅度上升。真空度越高，抽气速率越大、寿命越长的真空泵价格也就越贵，所以选择真空泵时一定要根据仪器的实际情况来选择！
The role of vacuum pump in the vacuum field is to extract gas molecules from the vacuum container, reduce the pressure of the gas in the vacuum container, and make it reach the required vacuum degree. With the rapid development of the application of vacuum industry, many manufacturers have developed many kinds of vacuum pump, its pumping rate from a few tenths of a liter per second to hundreds of thousands of liters per second, millions of liters. Generally speaking, there is a wide range from atmospheric pressure to extremely high vacuum, and so far no vacuum system can cover this range. Sometimes in order to meet the requirements of different product process indicators, working efficiency and equipment working life, different vacuum sections need to choose different vacuum system configuration.
Micro vacuum pump and gas sampling pump are often used in the field of medical instruments and instruments, with the flow rate below 20L/min. There are many kinds of micro vacuum air pumps, common rotary vane pumps, plunger pumps, film pumps and so on. In order to achieve the best configuration, the following points should be considered when selecting the micro vacuum air pump:
1. Determine the working vacuum range. Each industry has its own suitable vacuum range, the industry must first determine the vacuum required. For the gas sampling pump, if the gas itself has a certain negative pressure, then the vacuum parameters must also be considered.
2, determine the ultimate vacuum degree. Check the limit vacuum of vacuum pump system on the basis of determining the vacuum degree required by the industry, because the limit vacuum degree determines the best vacuum degree of vacuum pump. In general, the ultimate vacuum of the system is 20% lower than the operating vacuum of the system and 50% lower than the ultimate vacuum of the front stage pump. Instrument commonly used micro vacuum air pump vacuum degree can reach 10kPa.
3, determine the type, nature and pumping gas. If the delivery of high temperature, corrosive gas needs special diaphragm pump. The structure principle of each miniature vacuum pump is different. Some miniature vacuum pumps need to use lubrication and sealing liquid, which may react with the gas transported. Some may produce wear and tear, and also have to consider the pollution problem of the gas pumped. Micro diaphragm pump movement mechanism and transmission medium completely isolated, with no pollution medium, no leakage outstanding advantages, but the pumping volume is not as rotary vane vacuum pump.
To sum up, the cost performance of micro pump and sampling pump. Pump price is closely related to performance. The production of high vacuum, large flow, good reliability, long life of micro pumps, manufacturers need to have advanced fluid technology and rich experience, high-quality materials, high-precision machining and assembly, but also through long-term experiments, strict inspection selection. High technical indicators will lead to a substantial increase in pump costs. The higher the vacuum, the higher the pumping rate, the longer the life of the vacuum pump price is more expensive, so the choice of vacuum pump must be based on the actual situation of the instrument to choose!
