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:
Jul. 23, 1991
Filed:
Jun. 13, 1989
Fujio Tamura, Sendai, JP;
Abstract
A vacuum gauge for measuring pressure of environmental gas includes a quartz resonator disposed in the gas, and undergoing oscillation having a resonant frequency dependent on its body temperature which is dependent on relatively low pressure and having a resonant current which is dependent on relatively high pressure. Heat source is disposed adjacent to the resonator for supplying heat to the resonator so as to maintain the body temperature thereof and resonant frequency thereof according to the pressure of environmental gas, and producing an first output signal representative of value of the pressure in relatively low pressure range. A converter converts the resonant current of resonator into a corresponding second output signal representative of value of the pressure in relatively high pressure range. A meter indicates the value of pressure according to the first and second output signals.