The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 14, 1996
Filed:
Jun. 26, 1995
Luke D Hinkle, Townsend, MA (US);
MKS Instruments, Inc., Andover, MA (US);
Abstract
A pressure measurement and calibration apparatus for accurately detecting fluid pressures in the range of between approximately 0 and 1000 millitorr, and more particularly in the range of between 0 and 10 millitorr, and a method for calibrating an external pressure measuring device using the apparatus. The apparatus employs a pressure sensing assembly having a deflectable diaphragm and sensing electrodes. The assembly is rotated about an axis which is normal to the direction of local gravitational acceleration through preselected angles relative to the direction of local gravitational acceleration. The apparatus generates an output signal representative of the deflection of the diaphragm due to gravitational acceleration on the diaphragm at a given angular orientation. The apparatus then controllably conducts a fluid flow against the diaphragm at a sufficient pressure to substantially eliminate the deflection attributable to gravity on the diaphragm. The magnitude of the fluid pressure required to restore the diaphragm to its non-deflected state can then be computed with accuracy that is traceable to known primary standards.