Which device is used to monitor liquid refrigerant level?

• A. Thermometer
• B. Float switch
• C. Barometer
• D. Pressure gauge

Answer: (B)

Monitoring liquid refrigerant level is about detecting the actual presence of liquid in the receiver or reservoir. A float switch sits in the liquid and moves with it; as the level changes, the float operates a switch that can start or stop a pump or trigger an alarm. This direct sensing of liquid height is what you need to prevent issues like the compressor starving for liquid or reservoir overfill.

Temperatures (thermometer) are about how hot or cold something is, not how much liquid is present. Atmospheric pressure (barometer) has nothing to do with the refrigerant level. System pressure (pressure gauge) reflects pressure, which can be influenced by many factors and doesn’t give a direct measure of liquid level.