title: Wide vacuum pressure range monitoring by Pirani SAW sensor.
abstract: A new kind of surface acoustic wave (SAW) sensor has been developed to measure sub-atmospheric pressure below 100 mtorr with accuracy better than 0.1 mtorr. It provides an efficient measuring solution in the pressure range inaccessible in past by conventional diaphragm-based SAW sensors. Indeed, because of the small bending force in lower pressure and limited sensitivity, diaphragm-based SAW sensors are only suited to monitor relatively high pressure with a precision hardly better than 0.5 torr. To reach precision level better than 1 mtorr at sub-atmospheric pressure for vacuum technology applications, a radically different SAW-based solution is necessary. Our device aims to measure sub-atmospheric pressure less than 100 mtorr with a threshold resolution better than 0.1 mtorr. The concept is similar to the one used by Pirani pressure gauges. However, it is claimed that a heated and suspended SAW device should have better sensitivity. A theoretical model based on the basic concepts of gas kinetic theory and thermodynamics is presented. The validity of the model is checked by comparison between theoretical and experimental results.
authors.affiliation: LPMIA, UMR 7040 CNRS, Nancy University, 54506 Vandoeuvre-lès-Nancy, France
authors.forename: Pascal
authors.initials: P
authors.lastname: Nicolay
authors.forename: Omar
authors.initials: O
authors.lastname: Elmazria
authors.forename: Frederic
authors.initials: F
authors.lastname: Sarry
authors.forename: Laurent
authors.initials: L
authors.lastname: Bouvot
authors.forename: Hisanori
authors.initials: H
authors.lastname: Kambara
authors.forename: Kanwar J
authors.initials: KJ
authors.lastname: Singh
authors.forename: Patrick
authors.initials: P
authors.lastname: Alnot