Patent ID: 7159457

Claim:
A mass flow sensor to be located in a main duct, and comprising: a first sensor element, a second sensor element, and a recess in a body of the mass flow sensor, wherein the first sensor element provides a measuring signal that is representative of air mass flow (MAF) in the main duct ( 4 ) independently of a direction of flow of the mass flow (MAF) which flows past the first sensor element, the second sensor element is arranged in the recess and is coupled via a coupling element to the main duct ( 4 ) to provide a measurement signal responsive only to a flow of air in the main duct in a direction opposite to a main direction of air mass flow in the main duct, and the coupling element permits the recess to lie in a wind shadow of the main direction of flow of the mass flow (MAF) in the main duct ( 4 ) and brings about a flow of air mass in the recess counter to the main direction of flow of the air mass.