The so-called vacuum, is in a given space, the pressure is below 101325Pa gas state. In a vacuum, the leanness of a gas is usually expressed as the pressure of the gas. Obviously, the lower the pressure, the thinner the gas.
There are a variety of industrial vacuum pumps, for a variety of pump performance testing methods have a predetermined test, the main parameters are:
1, the ultimate vacuum (often referred to as vacuum): the vacuum pump connected to the test container, into the gas to be tested after a long time continuous extraction, when the gas pressure within the container does not decline and maintain a certain value, This pressure is called the pump's ultimate vacuum. The smaller the value, the closer it is to the theoretical vacuum.
Ordinary vacuum gauge measured vacuum (ie: gauge pressure) for the relative degree of vacuum, expressed in negative numbers, is measured gas pressure and atmospheric pressure difference.
2, pumping rate: in the vacuum pump suction port, the volume of gas flowing through the unit of time.
Traditional industrial vacuum pump volume is generally large, and the pump work requires special vacuum pump oil and lubricating oil, medium gas will contain a lot of oil mist.
With the development of instrumentation industry and people's environmental protection requirements, all kinds of miniature oil-free vacuum pumps came into being, generally have the following rules:
Pump price and vacuum indicators are closely related. The degree of vacuum indicator is the major indicator pursued by manufacturers in various countries. It reflects the overall strength of corresponding mechanical processing, sealing technology, material science and other fields, and is also an important means for manufacturers to obtain profits. To increase the vacuum index, there must be a higher sealing conditions, so you need to use more precise size, material properties and more excellent parts, so the production cost is greatly increased. And the price increase is much larger than the increase of vacuum index. Of course, the increase in pumping rate will also cause the price to rise, but its rate of increase is small. Therefore, the choice of micro-vacuum pump need to seriously develop the vacuum indicator, followed by the pumping rate, so as to best use both performance and cost.
High vacuum degree of micro-pump due to the use of a very precise sealing parts, so it's working conditions of the cleaning conditions, temperature parameters, medium composition and so have higher requirements.
Vibration and noise. Pump pumping speed and vacuum higher, the greater the vibration and noise.