Determination of thermal transpiration effect for biomolecular gases with capacitance manometer
Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
Capacitance manometer with sensors maintained at temperatures above the temperature of the vacuum vessel may read a higher gas pressure than the true value. This arises due to a transport process of molecules induced by molecule-surface collisions called thermal transpiration effect. Thermal transpiration effect depends on the pressure, the temperature gradient, gas, geometry and surface properties of the interconnecting pipe between the capacitance manometer and the vacuum vessel. To determine the height of the thermal transpiration effect for the biomolecular gas tetrahydrofuran, an experimental setup has been built. Its suitability to measure the thermal transpiration effect has been tested. Measurements of thermal transpiration effects for nitrogen and tetrahydrofuran have been analyzed with the semi-empirical Takaishi-Sensui equation. The coefficients of the Takaishi-Sensui equation can be used to determine the magnitude of the thermal transpiration effect for different temperature gradients, diameters of the interconnecting pipe and pressures.
Place, publisher, year, edition, pages
Thermal transpiration, vacuum, capacitance manometer, rarefied gas, tetrahydrofuran, vacuum physics, thermal creep, thermal transpiration effect, Takaishi-Sensui equation, microfluidics
Other Physics Topics
IdentifiersURN: urn:nbn:se:umu:diva-114529OAI: oai:DiVA.org:umu-114529DiVA: diva2:896757
Subject / course
Examensarbete i teknisk fysik
Master of Science Programme in Engineering Physics
2014-08-29, Universitetsklubben, Universum, 10:00 (English)
Baek, Woon Yong, Dr.
Lizana, Ludvig, Assistant Professor