NASA/TM-2004-213550, Albyn, K.C., Quartz Crystal Microbalance Operation and In Situ Calibration, George C. Marshall Space Flight Center , Marshall Space Flight Center, AL 35812, National Aeronautics and Space Administration, Washington, DC 20546-0001, November 2004, pp. 24, Format(s): PDF 1353k |
Quartz crystal microbalances (QCMs) are commonly used to measure the rate of deposition of molecular
species on a surface. The measurement is often used to select materials with a low outgassing rate for
applications where the material has a line of sight to a contamination-sensitive surface. A quantitative,
in situ calibration of the balance, or balances, using a pure material for which the enthalpy of sublimation
is known, is described in this Technical Memorandum. Supporting calculations for surface dwell times of
deposited materials and the effusion cell Clausing factor are presented along with examples of multiple
QCM measurements of outgassing from a common source.
| Keywords: | calibration, quartz crystal microbalance, deposition rate, effusion cell, view factor, frequency, enthalpy of sublimation, volatile condensable materials, clausing factor, surface dwell time, beat frequency, deposition measurement, outgassing |
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| Subjects: | Chemistry and Materials: Chemistry and Materials (General) |
| ID Code: | 690 |
| Deposited On: | 17 February 2005 |