Vacuum is defined as pressure that is?

Vacuum is defined as pressure that is below atmospheric pressure. This concept arises from the understanding that atmospheric pressure is the standard reference point for measuring pressure. When the pressure inside a container is reduced below this atmospheric level, a vacuum is created.

In practical terms, a vacuum can be created in various applications, such as in vacuum packaging or vacuum systems in certain industrial processes. The measure of how much lower the pressure is than atmospheric pressure can vary, leading to classifications of different types of vacuums (e.g., rough vacuum, medium vacuum, high vacuum, and ultra-high vacuum).

This definition is crucial in fields such as physics, engineering, and various industrial applications where controlling the pressure environment is essential for optimal results. Understanding what constitutes a vacuum helps in designing equipment that operates efficiently under controlled pressure conditions.