What is the Vacuum degree of pump vacuum?

- Feb 20, 2019-

What is the Vacuum degree of pump vacuum?


 IKS PVD,we are manufacture of PVD vacuum coating machine,contact with us now, iks.pvd@foxmail.com


Air pump rate

 vacuum4

The amount of air pumped is a measure of the speed of the vacuum pump. The general units are L/S and m cubed /h. Is to make up for leakage rate parameters. It is not difficult to understand why a vacuum pump with a large amount of air is easy to get the vacuum degree we need, while a vacuum pump with a small amount of air is slow or even unable to get the vacuum degree we want. Pipeline or container is always impossible to do absolutely no air leakage, and the large amount of air to make up for the air leakage caused by the reduction of vacuum factors, it is easy to draw the ideal vacuum value.

 

Vacuum degree

 

Represents the degree of thinness of a gas in a vacuum, usually expressed as a pressure value. Vacuum value is the value of the actual value of the system pressure is lower than the atmospheric pressure, the value expressed from the table is also known as table pressure, the industry also known as the limit of relative pressure, the actual application, vacuum usually has absolute vacuum and relative vacuum two kinds of words. The value read from the vacuum meter is called the vacuum degree. Vacuum = atmospheric pressure - absolute pressure (atmospheric pressure is generally 101325Pa, the limit absolute pressure of water ring vacuum pump is 3300Pa; Maximum absolute pressure of rotary vane vacuum pump (approx. 10Pa)

 

Vacuum

 

Theoretically, it means that there is nothing in the volume. (in reality, there is no real vacuum.) a vacuum is usually defined as one in which the pressure inside a container is lower than the normal atmospheric pressure (101,325 Pa).

 

Absolute and relative vacuum

 

Limiting relative pressure

 

The relative pressure is how much lower the measured internal pressure is than atmospheric pressure. Represents the actual value of the system pressure lower than the atmospheric pressure. As the air inside the container is pumped, the pressure inside the container is always lower than the pressure outside the container. When you write it in terms of the relative pressure or the surface pressure, you have to put a minus sign in front of it, which means that the pressure inside the container is lower than the external pressure.

 

Ultimate absolute pressure

The total pressure is how much higher the measured internal pressure is than the theoretical vacuum (theoretical vacuum pressure value is 0Pa). It compares the absolute vacuum pressure of the theoretical state. Due to the limitations of technology, we can never pump the internal pressure to the absolute vacuum of 0Pa. The vacuum value of the vacuum pump is higher than the theoretical vacuum value. So in terms of absolute vacuum, there's no minus sign in front of it.