A manometer is a precision instrument used to measure the pressure of gases or liquids, most commonly used in HVAC to check External Static Pressure (ESP). By measuring the air pressure inside your Ducted system, a technician can determine if your ducts are too small or if your filter is too restrictive. This tool is also essential for checking the gas manifold pressure in Mobile Home Gas Furnaces to ensure a clean and safe burn. We offer both digital and U-tube manometers in our Parts department for professional diagnostics. Using a manometer is the only way to scientifically verify that an Air Handler is moving the correct amount of air for the home. It takes the "guesswork" out of troubleshooting airflow issues and helps prevent ACIq system breakdowns. It is the gold standard tool for anyone serious about high-performance HVAC commissioning.