What is a deep vacuum usually measured in? (A) A) Inches of Hg (B) B) Psig (C) C) Microns (D) D) Psia

Deep vacuum is typically measured in microns, which is a unit that represents a billionth of a meter. This measurement indicates the level of vacuum achieved; the lower the micron value, the deeper the vacuum. For example, a deep vacuum might be in the range of 500 microns or lower, which is crucial in applications such as refrigeration and HVAC systems. Inches of Hg (mercury) is also a common unit for measuring vacuum, particularly in industrial settings. A vacuum gauge calibrated in inches of Hg indicates how much pressure has been reduced from atmospheric pressure. It's fascinating to note that one inch of Hg corresponds to approximately 25.4 mm of Hg, so different scales can help professionals select the right level of vacuum for their specific needs!