Here’s a quick lesson in pressure and vacuum terminology. If you’re going to speak the language of vacuums with those of us in the business, you’ll need to know these common pressure terms.
These are all the same thing. They can reference pressure or vacuum, but they are normally associated with dust collector fan performance. In vacuum systems, the terms are most often used when talking about pressure differential across a filter media.
Pounds per Square Inch. Most commonly used as a pressure term, but it can be a negative (vacuum) number.
Only used in ultra-high vacuum applications. Equals one millimeter of mercury (mmHg).
Inches of Mercury or Column of Mercury in inches. A measurement of vacuum, rarely used for pressure indication. The most common vacuum designation for the industrial class of vacuum systems.