Molecular Based Flow Measurement Techniques Molecular-based techniques allow measurement of fluid properties without seeding a flow with particles. Seeding flows with particles is difficult in many situations and provide erroneous results in others. Molecular-based techniques also allow measurement of multiple fluid properties including velocity, density, gas composition, sound speed, temperature, and Mach number. These molecular-based methods are used to study a wide variety of flows in subsonic, supersonic and hypersonic wind tunnels as well as combustion flows. The Advanced Measurements and Data Systems Branch (AMDSB) is developing and applying numerous molecular based single-point, multi-point and imaging techniques.
