HVAC/R JOURNEYMAN CDC 3E151 VOLUME 1
|ACTUAL QUESTIONS AND VERIFIED
ANSWERS|BRAND NEW 2026-2027
UPDATE|GRADED A+
Question 1
(001) When using a halide leak detector, the bluish flame turning green indicates
CORRECT ANSWER
a refrigerant leak
Question 2
(001) On a manifold gauge assembly, the vacuum hose is 3/8 inch and the other hoses are
1/4 inch because larger sizes allow for
CORRECT ANSWER
fewer restrictions which makes it easier and quicker to pull a vacuum
Question 3
(001) Why should the manifold gauge assembly not be used when measuring a vacuum?
CORRECT ANSWER
The gauge assembly reads inches of mercury and is not accurate when pulling deep vacuums
Question 4
(002) While taking a reading with an infrared thermometer, what happens as you get
further from the object being measured?
1
,CORRECT ANSWER
The reading becomes more inaccurate
Question 5
(003) What part of the combustion analyzer gets placed into the stack?
CORRECT ANSWER
The probe
Question 6
(003) What transfers flue gases from the boiler stack to the indicator unit?
CORRECT ANSWER
A tube and hand bulb
Question 7
(003) The special slide-rule calculator and CO2 indicator are used to determine
CORRECT ANSWER
combustion efficiency and stack loss
Question 8
(004) What will occur if you choose more than one conductor to measure when using a
clamp on meter?
CORRECT ANSWER
Incorrect readings
2
, Question 9
(004) A megohmmeter should never be used on a live circuit because
CORRECT ANSWER
it has its own power source and it will ruin the meter
Question 10
(004) A capacitance checker is used to test
CORRECT ANSWER
a capacitor
Question 11
(005) A photo tachometer is used to read the
CORRECT ANSWER
revolutions per minute (RPM) of a spinning motor shaft
Question 12
(005) When using a stroboscope, the frequency and reading is displayed for the technician
when the object appears to be
CORRECT ANSWER
standing still and the rpm of the equipment matches
3
|ACTUAL QUESTIONS AND VERIFIED
ANSWERS|BRAND NEW 2026-2027
UPDATE|GRADED A+
Question 1
(001) When using a halide leak detector, the bluish flame turning green indicates
CORRECT ANSWER
a refrigerant leak
Question 2
(001) On a manifold gauge assembly, the vacuum hose is 3/8 inch and the other hoses are
1/4 inch because larger sizes allow for
CORRECT ANSWER
fewer restrictions which makes it easier and quicker to pull a vacuum
Question 3
(001) Why should the manifold gauge assembly not be used when measuring a vacuum?
CORRECT ANSWER
The gauge assembly reads inches of mercury and is not accurate when pulling deep vacuums
Question 4
(002) While taking a reading with an infrared thermometer, what happens as you get
further from the object being measured?
1
,CORRECT ANSWER
The reading becomes more inaccurate
Question 5
(003) What part of the combustion analyzer gets placed into the stack?
CORRECT ANSWER
The probe
Question 6
(003) What transfers flue gases from the boiler stack to the indicator unit?
CORRECT ANSWER
A tube and hand bulb
Question 7
(003) The special slide-rule calculator and CO2 indicator are used to determine
CORRECT ANSWER
combustion efficiency and stack loss
Question 8
(004) What will occur if you choose more than one conductor to measure when using a
clamp on meter?
CORRECT ANSWER
Incorrect readings
2
, Question 9
(004) A megohmmeter should never be used on a live circuit because
CORRECT ANSWER
it has its own power source and it will ruin the meter
Question 10
(004) A capacitance checker is used to test
CORRECT ANSWER
a capacitor
Question 11
(005) A photo tachometer is used to read the
CORRECT ANSWER
revolutions per minute (RPM) of a spinning motor shaft
Question 12
(005) When using a stroboscope, the frequency and reading is displayed for the technician
when the object appears to be
CORRECT ANSWER
standing still and the rpm of the equipment matches
3
