HVAC HVAC Tools and Equipment 3

Question 1

Which instrument is used to measure static pressure within an HVAC duct system?

Accepted Answer

Manometer

Answer

A manometer (or digital pressure gauge) measures the static pressure difference between two points in a duct system, typically in inches of water column (in. w.c.).

Question 2

What is the purpose of a megohmmeter (megger) in HVAC electrical service?

Accepted Answer

Test insulation resistance of motor windings

Answer

A megohmmeter applies high DC voltage to motor windings to measure insulation resistance in megohms, revealing degraded or failing insulation.

Question 3

A capacitor tester is used in HVAC service to verify:

Accepted Answer

Microfarad (µF) rating of start and run capacitors

Answer

Capacitor testers measure actual capacitance in microfarads to confirm the capacitor meets its rated value, since a weak capacitor causes motor start and run problems.

Question 4

Which HVAC service tool uses ultrasonic technology to detect refrigerant or air leaks?

Accepted Answer

Ultrasonic leak detector

Answer

An ultrasonic leak detector senses the high-frequency sound produced by gas or air escaping through a small orifice, useful in noisy environments.

Question 5

What tool is used to measure the temperature difference (delta-T) across an evaporator coil to assess system performance?

Accepted Answer

Digital contact thermometer with dual probes

Answer

A digital thermometer with dual probes simultaneously reads supply and return air temperatures so the technician can calculate the actual temperature drop across the coil.

HVAC Practice Test

HVAC Practice Test

HVAC HVAC Tools and Equipment 3