Free Practice Quiz Question List

4 System Evacuation and Vacuum Verification Online Quiz Questions

Use this free practice quiz with 20 questions to review 4 System Evacuation and Vacuum Verification, test your knowledge, and prepare for your next test or exam.

20 questions

Choose one

1 point

A technician needs to verify that a refrigerant circuit has reached a deep vacuum. Which instrument is appropriate?

A
A conventional manifold gauge
B
A micron gauge
C
A recovery cylinder scale

True or false

1 point

A technician can use a 500-micron dehydration target as a substitute for the applicable EPA refrigerant-recovery level.

A
True
B
False

Written response

1 point

What instrument should be used to verify deep vacuum in a refrigerant circuit?

Choose one

1 point

A technician is setting up a micron gauge for evacuation. Where should the gauge be connected to best reflect pressure throughout the circuit?

A
At the vacuum pump outlet
B
On the recovery cylinder
C
On the system side, as far from the vacuum pump as practical
D
On the manifold gauge regardless of its connection

Choose all

1 point

Which practices support an effective evacuation setup? Select all that apply.

A
Use vacuum-rated hoses and sound connections.
B
Use appropriate core tools and adequately sized connections to reduce flow restrictions.
C
Use ordinary hoses that are not rated for vacuum because only the pump needs to hold vacuum.
D
Keep the system and tools clean and dry, and use the pump manufacturer's specified oil.

Written response

1 point

For many residential and light-commercial systems, what is the common upper limit of the dehydration target, subject to the manufacturer's instructions? Enter the value in microns.

True or false

1 point

During a standing vacuum test, the micron reading rises and then stabilizes above the allowed limit. This result by itself proves that the system has a leak.

A
True
B
False

Choose all

1 point

A micron reading continues to rise after the pump is isolated. Which responses are appropriate? Select all that apply.

A
Check the evacuation rig and its connections.
B
Use an approved pressure-test method to locate a suspected system leak, following the required procedure.
C
Treat vacuum decay alone as a definitive way to locate a leak.
D
Use oxygen to pressurize the refrigerant system.

Choose one

1 point

Why might a technician measure vacuum at more than one point in a large or branched system?

A
To make the vacuum pump run faster
B
To help reveal restrictions or uneven evacuation
C
To replace the need to follow the manufacturer's gauge instructions
D
To determine the EPA recovery level

Open ended

1 point

Explain how a standing vacuum test is conducted and what it can establish. Then distinguish it from the appropriate method for locating a suspected system leak.

Choose one

1 point

A technician is checking the required EPA refrigerant-recovery level for an appliance. Which statement best describes how that level is determined?

A
It is determined only by the 500-micron dehydration target.
B
It is the same for every appliance.
C
It varies by equipment pressure class, charge size, and recovery-equipment date.
D
It is determined only by the vacuum gauge location.

Choose one

1 point

A job specifies the EPA GreenChill example procedure for certain commercial refrigeration work. Which standing-test criterion matches that example?

A
Every residential and commercial system uses this acceptance criterion.
B
For certain commercial refrigeration work covered by EPA GreenChill guidance, the staged procedure ends at 300 microns, followed by a 24-hour stand with no more than 100 microns of drift.
C
The criterion defines the required EPA refrigerant-recovery level for all appliances.
D
The procedure allows no standing period once the system reaches 300 microns.

Choose one

1 point

What does a lower micron reading indicate when measuring a refrigerant circuit?

A
A higher micron reading means a deeper vacuum.
B
A lower micron reading means a deeper vacuum.
C
Microns measure the amount of refrigerant recovered.
D
A micron reading is a pressure value relative to atmospheric pressure.

True or false

1 point

A lower micron reading indicates lower absolute pressure and a deeper vacuum. True or false?

A
True
B
False

Written response

1 point

In deep-vacuum work, a micron is a unit of what physical quantity?

Choose one

1 point

Which test method should be used to locate a suspected leak in a refrigerant system?

A
An approved standing pressure leak test, following the applicable procedure.
B
A vacuum decay test alone, because it identifies the leak location.
C
A recovery-level check using EPA Section 608 evacuation requirements.
D
A deeper evacuation target, without performing a pressure test.

Choose one

1 point

After a system reaches its specified evacuation target, which procedure is a standing vacuum test?

A
Reach the specified target, isolate the system from the pump, and monitor the micron gauge for the specified period.
B
Keep the pump connected and use a manifold gauge to confirm that the pressure stays low.
C
Disconnect the gauge as soon as the target is reached and assume the system will hold.
D
Pressurize the system with compressed air while the pump continues to run.

Written response

1 point

In the stated EPA GreenChill example for certain commercial refrigeration work, a system ends the staged evacuation at 300 microns and is then left standing for 24 hours. What is the maximum allowed drift during that stand?

Fill in the blank

1 point

A contamination assessment finds gases in a refrigerant circuit that do not condense. What category of contaminant is evacuation intended to remove?

Fill in the blank

1 point

A procedure calls for breaking a system vacuum before an approved pressure test. Use dry as specified, and never pressurize the refrigerant system with or .

4 System Evacuation and Vacuum Verification Online Quiz Questions

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