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. 12, 1994
Filed:
Feb. 09, 1993
Japan National Oil Corporation, Tokyo, JP;
Abstract
A method and an apparatus capable of measuring the density of steam within a steam pipe even in limited environmental conditions such as in a steam injection well. A vessel which accommodates therein first and second neutron detectors disposed in mutual longitudinal alignment with a neutron source interposed therebetween and in which the second detector is covered with a neutron shield capable of absorbing thermal neutrons while allowing epithermal neutrons to penetrate therethrough is inserted into the steam pipe together with a thermal neutron shielding sheet completely encircling the vessel. From the neutrons which were emitted from the neutron source and passed out and back through the neutron shield and the steam region, those epithermal neutrons which have not undergone transformation to thermal neutrons within the steam region are detected by both the first and second detectors, while the thermal neutrons resulting from the transformation are detected by the first detector only. The steam density is determined on the basis of a cadmium ratio derived from the counts of the two detectors.