Type II — High-PressureQuestion 146 of 240
A technician needs to evacuate a Type II system to remove moisture and reaches 500 microns on the micron gauge. After isolating the pump, the reading climbs and stabilizes around 5,000 microns. What does this most likely indicate?
a.The system is perfectly dry and ready to charge
b.The micron gauge is broken
c.The vacuum pump is too powerful
d.Moisture is still present (or a small leak exists), so evacuation must continue
Explanation
When the vacuum rises and holds at a higher level after isolating the pump, it usually means moisture is still boiling off inside the system, or there is a small leak. The technician should continue evacuating, possibly using triple evacuation, until the vacuum holds at the target. A system is considered dry when the micron reading stays low and stable after isolation.
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