Use this option to adjust the minimum position command to meet the required minimum outdoor airflow rate as sensed by an airflow measuring station in the fresh air. There are two options for measuring the airflow, Velocity Pressure (Pitot Tube) or Flow Measurement (Scaled). Velocity Pressure adds an input for the velocity pressure and performs the calculation provided you enter the K factor and duct area for your system. Flow Measurement supports direct flow reading flow measurement devices. Either input must be scaled to match your sensing device.