Abstract: A fieldbus solenoid valve system has a solenoid operated control valve mounted and operated by a solenoid pilot. A direct current power source is connected to a coil of the solenoid pilot and a driver for actuating the coil. A resistive element is in series with the power source, the driver, the solenoid and a ground. A frequency generator is connected to the circuit for creating a frequency pulse train to the coil having a characterization so as not to cause the solenoid pilot to actuate. The voltage is measured between the coil and resistive element and the measured voltage is compared to a base voltage value measured from the same circuit location. An indicator signal is displayed on the fieldbus solenoid valve system or externally when the measured voltage increases to a predetermined amount from said base voltage over time.

Abstract: A fieldbus solenoid valve system has a solenoid operated control valve mounted and operated by a solenoid pilot. A direct current power source is connected to a coil of the solenoid pilot and a driver for actuating the coil. A resistive element is in series with the power source, the driver, the solenoid and a ground. A frequency generator is connected to the circuit for creating a frequency pulse train to the coil having a characterization so as not to cause the solenoid pilot to actuate. The voltage is measured between the coil and resistive element and the measured voltage is compared to a base voltage value measured from the same circuit location. An indicator signal is displayed on the fieldbus solenoid valve system or externally when the measured voltage increases to a predetermined amount from said base voltage over time.

Abstract: A slip ring includes a rotor and a stator. Stator contacts are connected to a data acquisition unit. The rotor contacts are connected to an amplifier circuit mounted in a housing connected to and rotatable with a rotating member. A sensor mounted on the rotating member to which the rotor is also fixedly mounted generates an electrical output signal corresponding to a sensed operating parameter of the rotating member. The sensor output signal is amplified by the amplifier in the housing before being transmitted through the slip ring to the data acquisition unit. Vibration isolation is provided when required for the slip ring and the circuit board in the housing carrying the amplifier to dampen vibrations generated by the rotating member. Resilient pads are mounted on the circuit board and engage the housing attached to the rotor.