公开(公告)号：CA2186450A1

公开(公告)日：1995-11-09

申请号：CA2186450

申请日：1995-04-27

Applicant: ROSEMOUNT INC

Inventor： SITTLER FRED C ,  HOWARD KATHRYN M

IPC: G01B7/00 ,  F16K37/00 ,  G01D5/12 ,  G01D5/14 ,  G01D5/16 ,  G01D5/245 ,  G01D5/249

Abstract: A magnet (16) mounted on a moving stem (12) or rotary member of a valve generates magnetic flux over part of a stationary member (14) of the valve which has a uniquely patterned set of magnetoresistive sense resistors (RSIG0RSIG4) and three reference resistors (130, 134, 148) disposed thereon. The distance between two adjacent patterns can be equally spaced, or can be compressed for valves with non-linear characteristics in order to achieve increased resolution over a specific portion of the valve travel. Other embodiments can use a light source, beta radiation or neutron radiation as the source of flux, the pattern for each embodiment's sensor having some material responsive and some unresponsive to the flux. The sensor (18) can provide feedback representative of position in a valve positioner, or functions as the position sensor in a position transmitter.