Which instrument provides a visual indication of moisture condition in a refrigerant system?

Which instrument provides a visual indication of moisture condition in a refrigerant system?

• A. Sightglass
• B. Pressure gauge
• C. Thermometer
• D. Hygrometer

Answer: (A)

A sightglass provides a visual indication of moisture in a refrigerant system. It’s a transparent window placed in the liquid line, so you can actually see the state of the refrigerant flowing through. When the refrigerant is dry, the liquid seen through the sightglass is clear. If moisture is present, the liquid often looks cloudy or milky, and you may see foam or bubbles indicating entrained vapor. Some sightglasses also include a built-in moisture indicator that changes color when water content is high, giving a direct visual signal of moisture levels. The other instruments measure different things—pressure, temperature, or ambient humidity—and don’t directly show moisture conditions in the refrigerant path.

A sightglass provides a visual indication of moisture in a refrigerant system. It’s a transparent window placed in the liquid line, so you can actually see the state of the refrigerant flowing through. When the refrigerant is dry, the liquid seen through the sightglass is clear. If moisture is present, the liquid often looks cloudy or milky, and you may see foam or bubbles indicating entrained vapor. Some sightglasses also include a built-in moisture indicator that changes color when water content is high, giving a direct visual signal of moisture levels. The other instruments measure different things—pressure, temperature, or ambient humidity—and don’t directly show moisture conditions in the refrigerant path.