Alleged vacuum, it is to point to be in given inside the space, pressure the aeriform condition under 101325Pa. Below vacuum condition, rare degree of gas expresses normally with pressure value of gas, apparent, this pressure value is less state gas is rarer. There are various vavuum pumps on industry, the test method that has a regulation to the function of all sorts of pump will examine, main parameter has: 1, ultimate vacuum (call vacuum to spend normally) : Will vavuum pump and detect container is linked together, put after waiting for measured gas, take president time successive bleed, when drop no longer when the aeriform pressure inside container and maintaining some to be worth surely, this pressure calls the ultimate vacuum of pump. This value is less make clear more adjacent and academic vacuum. 2, bleed rate: Be in the inspiratory mouth place of vavuum pump, the aeriform bulk that spend flows inside unit time. The tradition is industrial vavuum pump bulk is general very big, and the vavuum pump oil with the working special need of pump and lubricant engine oil, the meeting inside medium gas contains a large number of oily mist. As the requirement of the development of instrument bearing industry and people to environmental protection, the miniature of each country does not have emerge as the times require of oily vavuum pump, have the following law generally: The price of pump and vacuum spend index closely related. Vacuum spends index is the main index that business of each country production seeks hard, it reacted the integral actual strength of the domain such as science of corresponding machining, sealed technology, material, also be the important step that produces business to get profit. Want to raise vacuum to spend index, must have taller sealed requirement, because this needs to adopt measure the component with more superior performance of more accurate, material, then manufacturing cost rose substantially. And the amplitude that the amplitude of the price is more than vacuum to spend index far. Of course, of bleed rate rise to also meet those who cause the price climb litre, but its amplitude is not big. Accordingly, the need when choosing miniature vavuum pump makes vacuum spend index seriously, it is bleed rate next, performance characteristics of such ability best give attention to two or morethings and cost. Because the miniature pump that high vacuum spends used point-device sealed part, accordingly parameter of its clean condition to working environment, temperature, medium becomes classify to all have higher demand. Vibration and noise. The bleed rate of pump and vacuum are spent taller, vibration and noise are bigger also. CNC Milling