What does a Magnehlic gauge measure?

A Magnehlic gauge is specifically designed to measure pressure differences within systems, making it an essential tool for evaluating various aspects of HVAC performance and building diagnostics. It can provide readings in several units, including pascals, inches of water column, and psi. This capability is crucial for understanding the performance of ventilation systems, assessing duct leakage, and ensuring that pressure levels are appropriate throughout the building.

By using a Magnehlic gauge, technicians can identify issues related to airflow, identify the need for maintenance, and optimize system performance. This makes it a critical instrument in building performance assessments, as it directly contributes to understanding how effectively a building's heating, cooling, and ventilation systems operate.

In contrast, the other choices relate to different measures. Current temperature in Fahrenheit pertains to thermometers, airflow in CFM relates to anemometers, while moisture levels in air refer to hygrometers. Each of these tools serves a distinct purpose that does not overlap with the function of a Magnehlic gauge.