An introduction to the types of sensors used in a vacuum environment and the vacuum level

Mondo Digital Updated on 2024-01-31

Customers often have some sensors used in special environments, such as conventional sensors that need to be resistant to high temperature, low temperature, high pressure, explosion-proof and so on. There are some more special, such as vacuum environment, at this time we often need to consider the negative pressure bearing capacity of the product, whether it is the shell or cable, the core plate or the gel filled. Let's first introduce the environmental levels of vacuum.

1) Rough vacuum (105 102pa).

In the rough vacuum state, the characteristics of the gaseous space are not much different from the atmosphere, the number of gas molecules is large, and the thermal motion is still dominant, the collisions between molecules are very frequent, and the average free path of gas molecules is very short. As a rule, in this vacuum area, the main purpose of using vacuum technology is to obtain a pressure difference without requiring a change in the nature of the space. This is where the vacuum required for the vacuum impregnation process used in the production of capacitors is located.

2) Low vacuum (102-10-1pa).

In a low vacuum, the number of gas molecules per cubic centimeter is 1018 1018. The density of gas molecules is very different from the normal atmospheric pressure, and the charged particles in the gas will produce gas conductivity under the action of an electric field. At this time, the flow of the gas gradually transitions from the viscous stagnant state to the molecular state, and the kinetic properties of the gas molecules are obvious, and the convection phenomenon of the gas disappears completely. Therefore, if the metal is heated in this case, the chemical synthesis with the gas can be largely avoided, and the vacuum heat treatment is generally carried out in the low vacuum area. In addition, as the pressure in the container decreases, the boiling point of the liquid also decreases greatly, causing violent evaporation"Vacuum freezing dehydration"。In this vacuum region, the average free path of the molecules can be compared to the size of the container due to the decrease in the number of molecules in the gas, and the number of collisions between the molecules is reduced, while the number of collisions between the molecules and the wall of the container is greatly increased.

3) High vacuum (10-1 10-6 Pa).

In a high vacuum, the gas molecules are less dense and the number of molecules in the container is small. Therefore, the molecules rarely collide with each other in the process of movement, and the average free path of the gas molecules is greater than the linearity of the general vacuum container, and the vast majority of the molecules collide with the vessel wall. As a result, the molecules (or particles) of the material that evaporates in a high vacuum will fly in a straight line. In addition, due to the high vacuum in the container, the chemical interaction between any object in the container space and the residual gas molecules is very weak. In this state, the heat conduction and internal friction of the gas have become independent of the pressure.

4) Ultra-high vacuum (<10-6 Pa).

In ultra-high vacuum, the number of gas molecules per cubic centimeter is less than 100. Collisions between molecules are rare, and the molecules mainly collide with the walls of the container. One of the uses of ultra-high vacuum is to obtain pure gases, and the second is to obtain pure solid surfaces. At this time, the gas molecules are mainly adsorbed and stayed on the solid surface.

Vacuum technology can be used to obtain a vacuum state that is different from that of the atmosphere. The development and production of electronic materials, electronic components and semiconductor integrated circuits are closely related to vacuum technology. Vacuum technology has been widely used in industrial production, scientific experiments and high-tech research and other fields.

Nanjing Kitkit currently has the following products that can be customized for vacuum environment.

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