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:
Dec. 08, 2009
Filed:
Apr. 12, 2004
Ali Shajii, Canton, MA (US);
Siddharth P. Nagarkatti, Acton, MA (US);
Matthew Mark Besen, Andover, MA (US);
William R. Clark, Hampstead, NH (US);
Daniel Alexander Smith, Andover, MA (US);
Bora Akgerman, San Francisco, CA (US);
Ali Shajii, Canton, MA (US);
Siddharth P. Nagarkatti, Acton, MA (US);
Matthew Mark Besen, Andover, MA (US);
William R. Clark, Hampstead, NH (US);
Daniel Alexander Smith, Andover, MA (US);
Bora Akgerman, San Francisco, CA (US);
MKS Instruments, Inc., Wilmington, MA (US);
Abstract
A system for delivering a desired mass of gas, including a chamber, a first valve controlling flow into the chamber, a second valve controlling flow out of the chamber, a pressure transducer connected to the chamber, an input device for providing a desired mass to be delivered, and a controller connected to the valves, the pressure transducer and the input device. The controller is programmed to receive the desired mass from the input device, close the second valve and open the first valve, receive chamber pressure measurements from the pressure transducer, and close the inlet valve when pressure within the chamber reaches a predetermined level. The controller is then programmed to wait a predetermined waiting period to allow the gas inside the chamber to approach a state of equilibrium, then open the outlet valve at time=t, and close the outlet valve at time=t* when the mass of gas discharged equals the desired mass.