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. 25, 2018
Filed:
Jan. 03, 2017
Waters Technologies Corporation, Milford, MA (US);
Nigel Doe, Wilmington, DE (US);
Peter Foster, Avondale, PA (US);
WATERS TECHNOLOGIES COPRORATION, Milford, MA (US);
Abstract
A rheometer includes a drive shaft, a drag cup motor for rotating the drive shaft, a first measuring object supported by the drive shaft, a second measuring object, a linear position sensor, and processing and control electronics. The linear position sensor includes a target (e.g., an aluminum target) mounted to the drive shaft, and a pair of coils. The linear position sensor is configured to measure thermal expansion of the drive shaft based on a change in impedance of the coils resulting from a displacement of the target relative to the coils. The processing and control electronics are in communication with the coils and are configured to adjust a position of one of the measuring objects relative to the other based on a change in impedance of the coils resulting from a displacement of the target relative to the coils, thereby to maintain a substantially constant measurement gap therebetween.