What term describes any pressure below atmospheric in pneumatics?

In pneumatics, the term that refers to any pressure below atmospheric pressure encompasses various specific terms that describe this state. "Vacuum" generally indicates a condition where the pressure is significantly lower than the surrounding atmospheric pressure. This condition can also be categorized as a "partial vacuum," which denotes a specific level of lower pressure, but not to the extreme levels often associated with a full vacuum.

"Vacuum pressure" is another term used to describe the measure of pressure that is below atmospheric pressure, often indicated in negative values relative to atmospheric pressure. Each of these terms captures an aspect of the broader concept of pressures that are lower than what is typically found at sea level.

The inclusion of all these terms as options illustrates that in the field of pneumatics, different contexts may call for slightly varied terminology when discussing pressures below atmospheric levels. Therefore, recognizing that "vacuum," "partial vacuum," and "vacuum pressure" all describe this fundamental aspect of pressure dynamics in pneumatics justifies the answer that all of these terms are relevant and appropriate to the question about pressures below atmospheric levels.