Do you know the vacuum degree of the vacuum pump?

Air extraction

The pumping volume is a measure factor of the pumping speed of vacuum pump. General units are L / s and m ³/ H. It is a parameter to make up for the air leakage rate. It is not difficult to understand why a vacuum pump with large air volume can easily pump the vacuum we need, while a vacuum pump with small air volume is very slow or even unable to pump the vacuum we want? The pipeline or container can never be absolutely free of air leakage, and the large air extraction makes up for the decrease of vacuum caused by air leakage, and the air volume can easily reach the ideal vacuum value.

Vacuum pump

vacuum degree

It indicates the degree of gas dilution under vacuum, which is usually expressed by pressure value. The vacuum degree value indicates that the actual value of the system pressure is lower than the atmospheric pressure. The value expressed from the table is also called the table pressure, which is also called the limit relative pressure in the industry. In practical application, the vacuum degree usually has two versions: absolute vacuum and relative vacuum. The value read from the vacuum gauge is called vacuum degree. Vacuum degree = atmospheric pressure - absolute pressure (the atmospheric pressure is generally 101325pa, and the ultimate absolute pressure of water ring vacuum pump is 3300pa; Limit absolute pressure of rotary vane vacuum pump (about 10Pa)

Vacuum

Theoretically, it means that there is no substance in the volume. In reality, there is no real vacuum. Generally, the pressure in the container lower than the normal atmospheric pressure (101325 PA) is called vacuum state.

Absolute vacuum and relative vacuum

Limit relative pressure

The relative pressure is how much lower the measured internal pressure is than the "atmospheric pressure". It shows that the actual value of system pressure is lower than the value of atmospheric pressure. Because the air inside the container is pumped, the internal pressure is always lower than the external pressure of the container. When expressed by relative pressure or gauge pressure, the value must be preceded by a negative sign, indicating that the internal pressure of the container is lower than the external pressure.

Ultimate absolute pressure

Absolute pressure is how much higher the measured internal pressure is than "theoretical vacuum (theoretical vacuum pressure value is 0Pa)". It compares the absolute vacuum pressure of the theoretical state. Due to the limitation of process, we can't pump the internal pressure to the value of absolute vacuum 0Pa in any case. The vacuum value pumped by the vacuum pump is higher than the theoretical vacuum value. Therefore, when expressed in absolute vacuum, there is no negative sign in front of the value.
vacuum pump in semiconductor remover application