What vacuum level must the chamber achieve at sea level according to the procedure?

• A. 6 mm Hg
• B. 60 mm Hg
• C. 600 mm Hg
• D. 760 mm Hg

Answer: (A)

Vacuum levels are given in millimeters of mercury (mm Hg), and sea-level atmospheric pressure is about 760 mm Hg. A specification of 6 mm Hg means the chamber is pumped down to a pressure of only 6 mm Hg, which is a strong vacuum far below ambient. This level is used to effectively remove air (and sometimes moisture or volatile components) so that readings or processes inside the chamber aren’t influenced by air leaks or oxidation. The other options—60, 600, or 760 mm Hg—are progressively closer to atmospheric pressure, meaning they wouldn’t provide the strong vacuum required by the procedure. So the chamber must achieve around 6 mm Hg to meet the specification.