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:
Apr. 16, 1996
Filed:
May. 13, 1994
Dennis A Sierk, Huntsville, AL (US);
Ronald R DuRoss, Huntsville, AL (US);
Stephen G Geist, Union Grove, AL (US);
Gregory L Hayes, Fayetteville, TN (US);
SCI Systems, Inc., Huntsville, AL (US);
Abstract
A system including a plurality of gas flow control units in cabinets which are connected to distribute process gas, on demand, to a plurality of utilization locations known as 'tool' locations in a semi-conductor manufacturing plant. Transducers are used in the system to measure pressures and other control parameters. Zero calibration of the transducers is provided by automatically subjecting each transducer to a reference computer routine to compute the difference between the standard value and the transducer output, and store the difference as an 'offset' to correct the output of the transducer. Thus, re-calibration is performed simply and quickly, at a relatively low labor cost and with relatively little downtime for the system.