Which instrument does a technician use to confirm that a low-pressure appliance has reached the required recovery level?
Correct Answer
B) An electronic vacuum gauge that reads in absolute units
Confirming the recovery level requires an instrument that resolves pressures deep in the vacuum range, which means an electronic vacuum gauge calibrated in absolute units. It is connected to the appliance rather than to the recovery machine, because what matters is the pressure inside the vessel, not at the pump. Manifold compound gauges and the machine's own installed gauges have no usable resolution down there, and a leak detector measures concentration in air, not pressure inside a sealed shell.
Why This Is the Correct Answer
An electronic vacuum gauge reading absolute pressure is the only common instrument with useful resolution at the recovery level. Connecting it at the appliance rather than at the recovery unit also avoids being fooled by a hose or filter restriction that makes the pump side look deeper than the machine actually is.
Why the Other Options Are Wrong
Option A: The compound gauge on the recovery machine's manifold
A manifold compound gauge pins near the bottom of its scale long before the required level is reached, so it cannot confirm anything.
Option C: The machine's own condenser pressure gauge
The chiller's installed condenser gauge is built for operating pressures and is far too coarse to verify a deep vacuum.
Option D: An electronic refrigerant detector held at the service port
A refrigerant detector measures concentration in the surrounding air. It says nothing about the absolute pressure remaining inside the machine.
Memory Technique
Measure at the machine, not at the pump. The pump always lies deeper than the truth.
Reference Hint
Recovery level on low-pressure appliances is verified with an electronic absolute vacuum gauge connected at the appliance.
More epa-608-type-3 Questions
Some jobs on a chiller count as a major repair under the refrigerant rules, which changes what a technician is allowed to do with a badly leaking machine. Which job falls into that category?
An owner asks how many pounds of refrigerant the rules allow to be left inside a chiller once the recovery has been signed off. What is the correct answer to give him?
The motor of a hermetic centrifugal chiller sits inside the pressure boundary rather than outside it on a shaft. What follows from that construction?
An oxygen monitor is used to decide whether a chiller machine room is safe to enter after a refrigerant release. Below what oxygen reading is the atmosphere treated as oxygen deficient?
A low-pressure chiller's rupture disc has a discharge line running from it. Where does that line have to terminate?
A refrigerant vapor detector in a chiller machine room reaches its alarm level. Besides sounding, what is that alarm expected to do?
Which piece of equipment requires a technician to hold Type III certification before it may be serviced?
What property of the refrigerant is what actually places an appliance into the low-pressure category?
During normal operation, what condition exists inside the evaporator of a running low-pressure centrifugal chiller?
In what unit is the required final recovery vacuum for a low-pressure appliance normally expressed?
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