Patent ID: 8282781

Claim:
An apparatus, comprising: a sensor operable to measure a property of a sheet of material; and a sensor carriage operable to carry the sensor, the sensor carriage also operable to generate an air flow that is substantially tangential to the sheet in order to at least partially control a position of the sheet relative to the sensor carriage, wherein the sensor carriage comprises: a first slot in a first surface of the sensor carriage, the first slot configured to receive at least a portion of air from a first boundary layer of air associated with the sheet that is upstream from the sensor carriage; a second slot in a second surface of the sensor carriage, the second slot configured to provide at least a portion of air in a second boundary layer of air associated with the sheet that is downstream from the sensor carriage, the second surface on an opposite side of the sensor carriage than the first surface; and a third slot in a third surface of the sensor carriage, the third slot configured to provide the air flow that is substantially tangential to the sheet wherein at least the first and second slots are fluidly coupled to a chamber within the sensor carriage, the chamber adjacent to an area of travel of the sheet.