Abstract: A non-intrusive method for timing the full operational motion of a valve plug (26) in an electrically actuated, pneumatically operated valve (10). An actuation signal is sent to the valve actuator (54). A coil of wire (68) around the valve actuator solenoid (56), an accelerometer (70) on the solenoid slug (64), or a connection to a permanent pressure sensor (72), non-intrusively senses arrival of the actuation signal at the valve. The time measuring equipment (12) begins timing when the actuation signal is sensed. A laser valve motion sensor (74) then non-intrusively senses when the valve plug reaches a limit of motion. The time measuring equipment ends timing when the valve plug reaches a limit of motion. The time measuring equipment then records the elapsed time from the sensing of the arrival of actuation signal to the final limit of motion of the valve plug.

Abstract: Equipment for acquiring diagnostic data from a valve train parameter that changes as a result of the operation of a valve (14) in a process plant is positioned as an auxiliary data acquisition unit (200) in the vicinity of the valve train. A plurality of sensor lines (P3, P4) are connected between the auxiliary unit and locations in the valve train where the parameter changes. The valve is operated so as to generate parameter signals manifested in a first physical form in the sensor lines. In the auxiliary unit, the physical form of the parameter signals is converted into diagnostic signals (E10, E11) having a different physical form. The diagnostic signals are transmitted to a base data acquisition unit (100) that is physically distinct from the auxiliary unit.