Abstract: A functional test apparatus for a field device, particularly for a quick-acting gate valve for an emergency system, preferably of a chemical installation, of a gas burner or the like, with the field device configured to change or to be changed to a specific operating mode, particularly a safety or emergency operating mode, in case there is no power supply, comprises at least one device for detection of operating data for the field device, and at least one non-volatile memory for saving the detected operating data, at least one electrical energy buffer is provided which acts on the device for detention of operating data and on the non-volatile memory for supplying them with power, such that the operating data of the field device is detected and is saved in a non-volatile manner at least while the field device is making a transition to the specific operating mode.

Abstract: A method and a device test the operating safety of a process control device with a control element and an actuator to move the control element, as well as a position controller in a safety circuit. A control unit is connected with the position controller and is coupled to the actuator such that the actuator can be operated to move the control element from an initial condition to a final condition in the event of an incident with the aid of a controlling of the actuator by the control unit. A measurement device acquires measurement signals indicating movement of the control element from the initial condition. The position controller comprises a control signal generator to generate a control signal for partial movement of the control element in a test cycle for the process control device, and to transmit the control signal via a signal connection from the position controller to the control unit.

Abstract: A method and apparatus for detecting displacement of valve rod movement in electropneumatic position regulators, by generating a high-frequency electromagnetic alternating field by exciting a high-frequency oscillation within an LC oscillating circuit in an inductive sensor, damping the high-frequency oscillation as a function of displacement via an electrically conductive body moved along by the valve rod, demodulating the oscillator signal and feeding the demodulated signal to a microcomputer without amplification for evaluation of the displacement-dependent damping of the oscillation amplitude, measuring the temperature within the inductive sensor, correlating the temperature with the measured oscillation amplitude in the microcomputer, and determining a corrected displacement signal from the correlation.

Abstract: A device for operating a servo drive having a positioning element controlled by a pressure medium. The device includes an electrical control unit generating a control signal based upon the position of the positioning element, a pre-control system connected to receive the control signal through an electrical control path and a main control system controlled by the pre-control system to operate the servo drive by moving the positioning element. A switching element is positioned between the electrical control unit and the pre-control system and opens the electrical control path prohibiting the transmission of the control signal upon detecting operation malfunction. Upon opening of the control path, the pre-control system acts to switch the main control system into a deventilation mode and said positioning element is moved into a predetermined "fail safe" position deventilating the positioning volume of the drive.

Abstract: An apparatus and process for monitoring conditions of a control valve including a valve element operated by a drive controlled by a position controller. A spindle extends into a valve chamber through a dynamic seal and connects the valve element to the drive. The condition of the seal is monitored by measuring start-up time, stopping time and distance travelled. The start-up time relates to the time between application of control current to the position controller and sensing movement of the valve element. The stopping time relates to the interval between application of a second control current to the position controller and sensing the valve element has stopped. The distance travelled relates to distance the valve clement travels during the stopping time. A time difference is determined by subtracting the stopping from the starting time and is calibrated to a seal coefficient of friction. The distance travelled is also calibrated to a seal coefficient of friction.