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:
Jun. 11, 1996
Filed:
Feb. 02, 1994
Abdul Wajid, East Syracuse, NY (US);
Leybold Inficon Inc., , US;
Abstract
An acoustic technique is employed to identify the species of a refrigerant gas and whether it contains significant contaminants. Air in the refrigerant can be tolerated, but must be accounted for in determining the acoustic properties of the sample. The refrigerant is admitted into a Helmholtz resonator under a controlled pressure, and a drive frequency is applied to a transducer. Another transducer picks up the vibrations in the resonator and an output signal is compared to the drive signal to find resonant peaks and sharpness factors. The change in resonant frequency with pressure is measured, and is employed to quantify the presence of air in the sample. The amount of air present determines a frequency correction, which permits unambiguous identification of the species of refrigerant and of its purity.