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Full-Text Articles in Physics

Calibration Of Gas Flow Meters Using Choked Flow And An Evacuated Vessel, Max B. Trueblood, Otmar Schmid, Nicholas Altese, Christian J. Hurst, Wenyan Liu, Teresa Gelles, Steven C. Achterberg, Philip D. Whitefield, Donald E. Hagen Oct 2021

Calibration Of Gas Flow Meters Using Choked Flow And An Evacuated Vessel, Max B. Trueblood, Otmar Schmid, Nicholas Altese, Christian J. Hurst, Wenyan Liu, Teresa Gelles, Steven C. Achterberg, Philip D. Whitefield, Donald E. Hagen

Chemistry Faculty Research & Creative Works

The measurement of gas flow rates is of great importance in a wide range of modern technologies. This paper introduces a simple, yet accurate technique for in-house calibration of gas FMs (mass and volumetric) even under harsh environmental conditions such as encountered during field measurement campaigns. The method requires only readily available, low cost components: a vessel of known volume, an air pump, a pressure sensor and a metal plate orifice or a needle valve to act as a CO. The unique property of choked flow in the CO is used here for flow calibration. In the method presented here …


Observation Of New Particle Formation In The Northern Hemisphere At Altitude From 4 To 20 Km, Mohamed Saad Jan 2021

Observation Of New Particle Formation In The Northern Hemisphere At Altitude From 4 To 20 Km, Mohamed Saad

Electronic Theses and Dissertations

New particle formation (NPF) is investigated using measurements of aerosol size distributions and meteorological variables made in two continents, including USA and Europe. Despite the considerably different aerosol particle abundances among the sites, a common relationship was found between the characteristics of NPF events and the air mass convective and/or advective transport. CO and O3 act as tracers of tropospheric and stratospheric air, respectively, their statistical relationship can be used to quantify air mass characteristics and origins. The mixing ratio values of CO increased within the upper troposphere layer before/during NPF events, which may serve as an indicator of occurring …