A system includes a plurality of extraction passages configured to passively extract a portion of a gas flow from a downstream region of a gas flow path. The system includes a plurality of sensors respectively coupled to the plurality of extraction passages, wherein the plurality of sensors is configured to measure one or more parameters of the portion of the gas flow traversing the plurality of extraction passages. The system also includes a manifold coupled to the plurality of extraction passages, wherein the manifold is configured to receive the portion of the gas flow from the plurality of extraction passages. The system further includes a return passage coupled to the manifold, wherein the return passage is configured to passively provide the portion of the gas flow to an upstream region of the gas flow path.