Abstract: An apparatus for monitoring the pressure within a cask containing radioactive materials is disclosed. The apparatus comprises a differential pressure sensor sealingly connected to a bore that penetrates through the wall of the cask for directly monitoring the pressure of the helium gas contained within the cask and for providing a first barrier between the helium gas and the ambient atmosphere. An evacuated sensor chamber surrounds both the outlet end of the through-wall bore and the differential pressure sensor for providing a second barrier between the helium and the ambient atmosphere as well as a vacuum reference point for the differential pressure sensor. An absolute pressure sensor is connected in parallel to the through-wall bore to allow the system operator to determine whether or not a reduction in the pressure sensed by the differential pressure sensor is the result of a leakage condition in the cask, or in the evacuated sensor chamber.

Abstract: The present invention is a component monitoring system which includes all sensor and plant component monitoring at distributed plant locations close to the sensors which are the source of the signals to be analyzed. Minimally preconditioned analog sensor signals are multiplexed and further conditioned by a sensor signal preprocessor that adjusts the gain and filters the sensor signals before being applied to an analog-to-digital converter controlled by a data acquisition computer. The analog sensor signals are converted into digital samples and stored in a data memory of a digital signal processor using a direct memory access technique. The data acquisition computer also controls the selection of sensors, gain, etc., based on commands from a controller. The digital signal processor, once sufficient sensor data has been collected, performs appropriate processing using known digital signal processing techniques.

Abstract: In a method and apparatus for reducing the effects of frequency burst noise and noise spikes accompanying a random pulse signal, pulses with an amplitude above a high threshold or below a low threshold are eliminated, with the remaining pulses of intermediate amplitude being statistically filtered. The statistical filter compares the current pulse count rate signal to maximum and minimum statistical limits generated from the recent average value of the pulse count rate using Poisson statistics, and clamps the output to the limit which is exceeded. If the pulse count rate is between the statistical limits, it is used as the output pulse count rate signal. If the statistical limits are exceeded for a designated interval indicative of a true change in the pulse count rate, clamping of the output signal is overridden so that the true change in pulse count rate can be tracked. Statistical filtering is resumed when the current pulse count rate is again within the statistical limits.

Abstract: A magnetic displacement transducer system for measuring the movement of a member includes an elongated permanent magnet which is mechanically coupled to the member so that the magnet moves parallel to its axis. A magnet-position sensor assembly, which includes at least one magnetometer having an elongated ferromagnetic core with a coil wrapped around it, is positioned adjacent the magnet so that the axis of the core and coil intersects the axis of the magnet at right angles. A pair of wires carry a sinusoidal excitation current to the assembly, convey the second harmonic from the assembly, and deliver a DC biasing current to the assembly in order to null the component of the permanent magnet's field that is perpendicular to the axis of the magnet. The value of the DC biasing current is measured to obtain the displacement of the member.