Nate core exam UPDATED Study Guide
QUESTIONS AND CORRECT ANSWERS
What makes a contract legal? - CORRECT ANSWERS Any verbal or
written agreement.
Why should hacksaws and power saws not be used when cutting tubing or
refrigerant lines? - CORRECT ANSWERS The small shavings created
by the teeth of the saw can enter the tubing and do damage to the components of
the system.
Why should tube cutters be used? - CORRECT ANSWERS They
produce a square, clean cut and leave no shavings to contaminate the system.
What can be used to cut capillary tubing? - CORRECT ANSWERS A
triangular file or a knife edge file.
How should tubing be cut? - CORRECT ANSWERS It should be scored
all the way around the outside and then snapped to prevent closing of the inside
diameter.
What can be used to remove a burr on the inside of tubing? - CORRECT
ANSWERS Reamers and deburrers.
What does burring cause on the inside of tubing? - CORRECT ANSWERS
It can create turbulence and pressure drop inside the piping.
What can be used on soft drawn copper to provide a bend without kinking or
damaging the tubing? - CORRECT ANSWERS Tube benders.
,Spring-Type benders can only be used on what type of tubbing? - CORRECT
ANSWERS Soft drawn copper
What is the purpose of a flaring tool? - CORRECT ANSWERS It allows
you to join soft drawn copper tubing without the use of a coupling.
What is the purpose of a swaging tool? - CORRECT ANSWERS A
method of joining tubing without a fitting.
After flaring, swaging, and connecting the tubing, what do you do next? -
CORRECT ANSWERS You either solder or braze the connection.
Describe the glass stem thermometer. - CORRECT ANSWERS It has a
liquid filled tube marked off with a graduated temperature scale.
What are some characteristics of a dial stem thermometer? - CORRECT
ANSWERS Not quite as accurate as the glass stem thermometer, but it is
low cost and durable.
What do the glass stem thermometer and the dial stem thermometer measure? -
CORRECT ANSWERS Dry-bulb temperature.
What temperature is in relation to human comfort? - CORRECT ANSWERS
Dry-bulb temperature.
What is a sling psychometer? - CORRECT ANSWERS It combines glass
stem thermometers to measure both dry-bulb and wet-bulb temperatures.
What is needed with the sling psychometer to measure temperatures? -
CORRECT ANSWERS A psychometric chart or slide rule.
, What can the dry-bulb and wet-bulb temperatures be used to determine? -
CORRECT ANSWERS Relative humidity (%RH) The dew points. Other
properties of the air.
What can be used to calculate the relative humidity, dew point, and other
properties of the air? - CORRECT ANSWERS The difference between
the wet-bulb and the dry-bulb temperature.
Explain the effects of relative humidity. - CORRECT ANSWERS By
increasing the humidity during the heating season, the evaporation of moisture
is slowed, therefore you feel warmer and vice versa.
What is the digital psychrometer able to do? - CORRECT ANSWERS It
is capable of reading dry-bulb and wet-bulb temperature and %RH.
How do you find absolute pressure? - CORRECT ANSWERS Gauge
pressure + 14.7PSI
What does a pressure gauge use as the operating element? - CORRECT
ANSWERS A bourdon tube.
Describe the manifold gauge set. - CORRECT ANSWERS On the right =
High pressure (Liquid) (discharge gauge) (Red) On the left = Compound or
suction gauge (Blue) (Vapor)
What is often used to measure pressure drop? (The difference in pressure
between two points.) - CORRECT ANSWERS Differential pressure
gauges.
QUESTIONS AND CORRECT ANSWERS
What makes a contract legal? - CORRECT ANSWERS Any verbal or
written agreement.
Why should hacksaws and power saws not be used when cutting tubing or
refrigerant lines? - CORRECT ANSWERS The small shavings created
by the teeth of the saw can enter the tubing and do damage to the components of
the system.
Why should tube cutters be used? - CORRECT ANSWERS They
produce a square, clean cut and leave no shavings to contaminate the system.
What can be used to cut capillary tubing? - CORRECT ANSWERS A
triangular file or a knife edge file.
How should tubing be cut? - CORRECT ANSWERS It should be scored
all the way around the outside and then snapped to prevent closing of the inside
diameter.
What can be used to remove a burr on the inside of tubing? - CORRECT
ANSWERS Reamers and deburrers.
What does burring cause on the inside of tubing? - CORRECT ANSWERS
It can create turbulence and pressure drop inside the piping.
What can be used on soft drawn copper to provide a bend without kinking or
damaging the tubing? - CORRECT ANSWERS Tube benders.
,Spring-Type benders can only be used on what type of tubbing? - CORRECT
ANSWERS Soft drawn copper
What is the purpose of a flaring tool? - CORRECT ANSWERS It allows
you to join soft drawn copper tubing without the use of a coupling.
What is the purpose of a swaging tool? - CORRECT ANSWERS A
method of joining tubing without a fitting.
After flaring, swaging, and connecting the tubing, what do you do next? -
CORRECT ANSWERS You either solder or braze the connection.
Describe the glass stem thermometer. - CORRECT ANSWERS It has a
liquid filled tube marked off with a graduated temperature scale.
What are some characteristics of a dial stem thermometer? - CORRECT
ANSWERS Not quite as accurate as the glass stem thermometer, but it is
low cost and durable.
What do the glass stem thermometer and the dial stem thermometer measure? -
CORRECT ANSWERS Dry-bulb temperature.
What temperature is in relation to human comfort? - CORRECT ANSWERS
Dry-bulb temperature.
What is a sling psychometer? - CORRECT ANSWERS It combines glass
stem thermometers to measure both dry-bulb and wet-bulb temperatures.
What is needed with the sling psychometer to measure temperatures? -
CORRECT ANSWERS A psychometric chart or slide rule.
, What can the dry-bulb and wet-bulb temperatures be used to determine? -
CORRECT ANSWERS Relative humidity (%RH) The dew points. Other
properties of the air.
What can be used to calculate the relative humidity, dew point, and other
properties of the air? - CORRECT ANSWERS The difference between
the wet-bulb and the dry-bulb temperature.
Explain the effects of relative humidity. - CORRECT ANSWERS By
increasing the humidity during the heating season, the evaporation of moisture
is slowed, therefore you feel warmer and vice versa.
What is the digital psychrometer able to do? - CORRECT ANSWERS It
is capable of reading dry-bulb and wet-bulb temperature and %RH.
How do you find absolute pressure? - CORRECT ANSWERS Gauge
pressure + 14.7PSI
What does a pressure gauge use as the operating element? - CORRECT
ANSWERS A bourdon tube.
Describe the manifold gauge set. - CORRECT ANSWERS On the right =
High pressure (Liquid) (discharge gauge) (Red) On the left = Compound or
suction gauge (Blue) (Vapor)
What is often used to measure pressure drop? (The difference in pressure
between two points.) - CORRECT ANSWERS Differential pressure
gauges.
