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. 28, 1976
Filed:
Oct. 01, 1975
Toshihiro Mihara, Hirakata, J;
Masatake Ayusawa, Hirakata, J;
Keiji Matsumoto, Ibaragi, J;
Kunio Sato, Neyagawa, J;
Yoshio Iida, Suite, J;
Abstract
This invention provides a reducing gas sensor which has a gas sensitive element of .gamma.-ferric oxide (.gamma.-Fe.sub.2 O.sub.3), a pair of electrodes and a heater element. The .gamma.-ferric oxide is in the form of a thin film, a plate or a thin surface layer on a sintered plate of .alpha.-ferric oxide. This invention also provides a method of producing the reducing gas sensor, which includes the steps of firing .gamma.-Fe.sub.2 O.sub.3, .gamma.-FeOOH or Fe.sub.3 O.sub.4 powder on a substrate and applying thereto a pair of electrodes and a heater element; or sintering alpha-ferric oxide (.alpha.-Fe.sub.2 O.sub.3) and reducing it to magnetite and oxidizing it at the surface thereof to .gamma.-ferric oxide as a gas sensitive element. The sensitivity (R.sub.A /R.sub.G) of the gas sensitive element of .gamma.-ferric oxide is 10 to 130.degree. at 270.degree. C in an atmosphere containing 0.1 to 1 percent by volume propane gas, and the reducing gas sensor has high sensitivity and stability.