Abstract: A fluid flow damper for use within a duct includes a first blade having a wing section and a base section. The damper also includes a second blade having a wing section and a base section engaged with the base section of said first blade. A first passage is defined by the base section of the first blade with one or more ports providing fluid communication between the passage and a fluid upstream of the damper within the duct in order to measure the velocity pressure plus static pressure within the duct. Additionally, a second passage is defined by the base section of the second blade with one or more ports providing fluid communication between the passage and a fluid downstream of the damper within the duct in order to measure the static pressure within the duct.