EPA 608 Core · Dehydration & Evacuation · Easy
What tool is required to accurately measure a deep vacuum?
Answer: B. A micron gauge.
- AA standard manifold gauge.
- BA micron gauge.✓ Correct
- CA digital scale.
- DA psychrometer.
Why B is right
A deep vacuum is measured in microns of mercury: 1 micron is 1/1,000 of a millimeter of mercury, and 1 inch of mercury is 25,400 microns. A manifold gauge can't read that fine, so a micron gauge is required; 500 microns is the usual dehydration target.
More Core questions
- What is the standard target vacuum level for system dehydration?
- What happens to the boiling point of water as system pressure drops in a vacuum?
- If a micron gauge rises to atmospheric pressure after the pump is off, what does it mean?
- If a micron gauge rises and then levels off (e.g., at 2000 microns), what does it mean?
- What is the primary purpose of evacuating a refrigeration system?
Go deeper with the study guide EPA 608 Evacuation Levels: The Required Vacuum by Appliance, try the free 10-question test or browse all EPA 608 practice questions.
A practice question written for study, checked against 40 CFR Part 82, Subpart F. It is not an official EPA exam question, and this site is not affiliated with the U.S. EPA.