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Study of cavity effect in micro-Pirani gauge chamber with improved sensitivity for high vacuum regime
- Source :
- AIP Advances, Vol 8, Iss 5, Pp 055131-055131-7 (2018)
- Publication Year :
- 2018
- Publisher :
- AIP Publishing, 2018.
-
Abstract
- Ultra-low pressure application of Pirani gauge needs significant improvement of sensitivity and expansion of measureable low pressure limit. However, the performance of Pirani gauge in high vacuum regime remains critical concerns since gaseous thermal conduction with high percentage is essential requirement. In this work, the heat transfer mechanism of micro-Pirani gauge packaged in a non-hermetic chamber was investigated and analyzed compared with the one before wafer-level packaging. The cavity effect, extremely important for the efficient detection of low pressure, was numerically and experimentally analyzed considering the influence of the pressure, the temperature and the effective heat transfer area in micro-Pirani gauge chamber. The thermal conduction model is validated by experiment data of MEMS Pirani gauges with and without capping. It is found that nature gaseous convection in chamber, determined by the Rayleigh number, should be taken into consideration. The experiment and model calculated results show that thermal resistance increases in the molecule regime, and further increases after capping due to the suppression of gaseous convection. The gaseous thermal conduction accounts for an increasing percentage of thermal conduction at low pressure while little changes at high pressure after capping because of the existence of cavity effect improving the sensitivity of cavity-effect-influenced Pirani gauge for high vacuum regime.
- Subjects :
- 010302 applied physics
Convection
Materials science
Thermal resistance
Ultra-high vacuum
General Physics and Astronomy
02 engineering and technology
Rayleigh number
Mechanics
Gauge (firearms)
021001 nanoscience & nanotechnology
Thermal conduction
01 natural sciences
lcsh:QC1-999
Pirani gauge
0103 physical sciences
Heat transfer
0210 nano-technology
lcsh:Physics
Subjects
Details
- ISSN :
- 21583226
- Volume :
- 8
- Database :
- OpenAIRE
- Journal :
- AIP Advances
- Accession number :
- edsair.doi.dedup.....03a9c85c6466eb1311b0b117e497b85f