What does a magnehelic gauge measure?

A magnehelic gauge specifically measures static pressure in a duct system, which is crucial for assessing the effectiveness of ventilation systems. Static pressure is the pressure exerted by air at rest and helps determine how much air is available to flow through a duct system versus how much is actually moving. Monitoring static pressure drop allows technicians to evaluate the performance of filters, fans, and other components within the system, ensuring optimal operation and energy efficiency.

While air flow rate is related to how air moves, the magnehelic gauge does not directly measure the flow itself but rather the pressure conditions that affect flow. Similarly, it does not measure temperature variations or fluid velocity; those would require different types of instruments designed for those specific purposes. Thus, understanding static pressure using a magnehelic gauge is vital for effective system design and troubleshooting in refrigeration and HVAC applications.