Which tool is used to check the gas pressure in a refrigeration system?

• A. Multimeters
• B. Thermometers
• C. Manometers
• D. Oscilloscopes

Answer: (C)

Measuring gas pressure in a refrigeration system is done with a device that compares the refrigerant pressure to a fluid column. That device is a manometer. It shows the pressure as a column height of liquid, giving you either gauge pressure (relative to atmospheric pressure) or absolute pressure depending on the type used. In HVAC work, you use it to read suction and discharge pressures to evaluate proper charge and performance. Multimeters measure electrical values, thermometers measure temperature, and oscilloscopes display electrical waveforms—none of these directly measure refrigerant pressure, so they aren’t suitable for checking gas pressure in the system.