Abstract: A method of analyzing vibrations of a rolling element bearing installed in a rotating machine includes accessing vibration data corresponding to the bearing to be analyzed, determining a degraded condition factor BD for the bearing, selecting an expected designer-determined mean-time-to-failure MTTF of the bearing operating under a design load in the operating environment of the rotating machine, selecting a forecast time period, calculating a reduced mean-time-to-failure RMTTF of the bearing using the expected designer-determined mean-time-to-failure MTTF and the degraded condition factor BD, calculating a probability of failure of the bearing in the forecast time period using the reduced mean-time-to-failure RMTTF, accessing cost data corresponding to a cost of failure of the bearing in the rotating machine, calculating a financial risk from the calculated probability of failure in the forecast time period and the cost data, and displaying the financial risk for the selected time period.

Abstract: A method of analyzing vibrations of a rolling element bearing installed in a rotating machine includes accessing vibration data corresponding to the bearing to be analyzed, determining a degraded condition factor BD for the bearing, selecting an expected designer-determined mean-time-to-failure MTTF of the bearing operating under a design load in the operating environment of the rotating machine, selecting a forecast time period, calculating a reduced mean-time-to-failure RMTTF of the bearing using the expected designer-determined mean-time-to-failure MTTF and the degraded condition factor BD, calculating a probability of failure of the bearing in the forecast time period using the reduced mean time to failure RMTTF, accessing cost data corresponding to a cost of failure of the bearing in the rotating machine, calculating a financial risk from the calculated probability of failure in the forecast time period and the cost data, and displaying the financial risk for the selected time period.

Abstract: A system and method for monitoring and analyzing vibrations in a rotating machine having rolling bearing elements where the method comprises providing an accelerometer to detect an acceleration signal indicative of machine vibration, filtering the vibration signal for signal frequencies indicative of bearing surface defects and converting the RMS value of the signal frequencies to a first DC voltage, determining the RMS value of the acceleration signal and converting the RMS value to a second voltage; determining the peak value of the acceleration signal, determining the ratio of the peak value to the RMS value of the acceleration signal and converting the ratio to a third DC voltage; determining the square of the peak value of the acceleration signal, determining the ratio of the squared peak value to the value of the second voltage to provide a fourth DC voltage indicative of the ratio; detecting a signal at the resonant frequency of the accelerometer, demodulating the detected signal at the resonant freque

Abstract: The Multiple Discriminant Analysis system described provides three parameters: (1) a Dynamic Force Factor (DFF) that characterizes the dynamic forces which act to reduce operational life of the bearing; (2) a Bearing Degradation Factor (BDF) that characterizes the actual condition of the rolling element bearing; and (3) a Life Expectancy Factor (LEF) that characterizes the overall condition of the first two factors. Each factor is configured in scalar form, wherein readings range from acceptable, to caution/degradation, to action required. DFF combines low frequency and high frequency dynamic forcing function discriminants. BDF combines, in this case, four powerful diagnostic bearing fault process discriminants, in a formulaic composition. The composition accurately describes the actual rolling element bearing condition indicating optimum or warning of a potential failure condition. The normally voluminous vibration data is compressed into three easily understood, yet highly informative numbers.

Abstract: An accelerometer providing shear isolation from unwanted shear forces by means of a shear isolation member located inside the accelerometer housing. The shear isolation member is rigidly attached to the housing at a mounting end and one or more piezoelectric crystals are mounted on a crystal mounting region. The mounting end is sufficiently far from the crystal mounting region that shear forces exerted on the accelerometer housing are not transmitted through the mounting end to the crystal mounting region, while vibrations, which affect the entire accelerometer, produce shear forces in the crystal which are easily detected.

Abstract: A multipoint data collection system uses multiple parallel data buses connecting a central controller to addressable sensor interfaces to permit any sensor to be connected to a central controller over any one of the data buses. Both ends of each data bus are connected to the central controller, allowing sensor interfaces to be addressed even if all data buses are cut. Faults on a data bus and defective sensor interfaces may be bypassed through one or more bypass buses that may be addressably switched into use as desired.

Abstract: An accelerometer with internal electronics is mounted within a Faraday shield and encapsulated within a non-electrically conductive material applied by hot injection molding at a high pressure to form a hermetically sealed case with integral strain-relief, cable bend protection, ground loop isolation and protection against EMI/RFI interference through both conduction and radiation. The accelerometer is shaped as a torus with the center hole providing center hole bolt mounting.

Abstract: A multipoint data collection system uses multiple parallel data buses connecting a central controller to addressable sensor interfaces to permit any sensor to be connected to a central controller over any one of the data buses. Faults on a data bus may be bypassed, or multiple sensors monitored simultaneously in real time, through the use of the parallel data buses. Digital address signals and analog data are transmitted on the same data bus, distinguished from one another by restricting the voltage range of the analog data to voltages above the voltage corresponding to a digital zero and below the voltage corresponding to a digital one.

Abstract: An apparatus for monitoring a vibrating structure, such as a bridge, uses multiple motion sensors spaced along the structure, each of which produces an analog raw data signal which is then filtered in anti-aliasing filters to remove substantially all frequency components of the signal above a selected cutoff frequency, f.sub.co. The filter outputs are connected to addressed inputs of an analog multiplexer which then multiplexes the signals in response to a channel address clock which repeatedly generates a sequence of channel addresses to scan the data input channels at the multiplexer corresponding to the addresses in the sequence. The complete sequence of addresses is repeated at a frequency of at least twice the cutoff frequency to obtain substantially simultaneous samples from the sensors so that data from different sensors may be correlated. The multiplexed signal is then converted to digital form and stored.