Coast Guard Exams
Question 97Refrigeration/AC - Assistant Engineer70% to pass

Using the illustrated chart giving the boiling point of moisture at various depths of vacuum, with an ambient temperature of 72°F, what depth of vacuum would be associated with the BEST chance of achieving a dehydration evacuation with a deep vacuum pump? Illustration GS-RA-56

AI Explanation
The correct answer is D) 29.99" Hg or 254 microns of Hg absolute. This is the correct answer because at 29.99" Hg or 254 microns of Hg absolute, the boiling point of moisture is the lowest, which would provide the best chance of achieving a dehydration evacuation with a deep vacuum pump. The lower the boiling point of moisture, the more effective the vacuum pump will be at removing moisture. The other options, while they represent high vacuum levels, do not correspond to the lowest boiling point of moisture based on the provided chart. Therefore, they would not be the optimal choice for a dehydration evacuation using a deep vacuum pump.