Method of and apparatus for determining the position of a movable member

摘要

The position of a valve member is sensed by a transducer mounted on the exterior of the valve housing. The transducer is connected to a passive circuit located within an enclosure mounted on or adjacent to the valve housing. The passive circuit, when connected to a source of electrical power, provides a signal commensurate with the output of the transducer and an encoded signal which identifies the valve. The information contained in these signals is transmitted to a remote location, decoded and employed to determine the existance of a valve member position error.