Vacuum level
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The absolute pressure we usually refer to is zero, while the vacuum level is -0.1 Mpa. Is there a state at -0.15 Mpa?
Unless on a planet where the atmospheric pressure is 0.15 MPa near sea level. Forget Earth. Vacuum degree is a relative value
The vacuum degree value represents the extent to which the actual pressure in a system is lower than atmospheric pressure; that is, Vacuum Degree = Atmospheric Pressure – Absolute Pressure. The absolute pressure can only approach 0 infinitely, so the maximum value of the vacuum degree is one atmosphere
Gauge pressure uses the theoretical zero pressure as the reference point for measurement, while vacuum pressure uses the ambient atmospheric pressure at the location where the instrument is operating as the reference point. If vacuum pressure is to be used, then it refers to an absolute vacuum. . . . So, when drilling a shaft 5000 meters deep, having some guy carry a vacuum pump and jump down to extract air from there – achieving a pressure of -0.15 MPa is completely insignificant; it’s not even worth mentioning. Reaching -0.20 MPa is still considered a trivial achievement, and -0.25 MPa is just a negligible value {:3_51:}. To be sensible, one must thoroughly understand the concepts related to pressure. Source: Training materials for villagers provided by Shaanxi Shuaike Sensing Instrument Manufacturing Company. .
No, no vacuum pump can meet this requirement.
If one can understand this diagram correctly, the concepts of several types of pressure will become clear.