The Measurement of Multiple 0.1 - 10 Torr Differential Pressures in Subatmospheric Wind Tunnel Flows

Abstract : A system for measuring multiple 0.1-10 Torr differential pressures has been assembled, tested in the laboratory, and used in actual wind tunnel tests. The system accepts 141 pressure inputs, but can easily be expanded for more inputs. Off-the-shelf items were used, including three 48-port mechanical scanner valves and three capacitance transducers. Equipment, procedures, and results from the laboratory experiments are described in detail. Results from tests on the effects of the scanner valves on overall accuracy and pneumatic lag time at line pressures between 235 and 760 Torr, absolute are of particular interest.