Abstract: A device attached to a railcar of a train is provided. The device comprises a radio frequency (RF) transceiver to transmit and receive a RF signal. The device includes a RF modem configured to convert the received RF signal into a low frequency (LF) analog signal. The device includes a digital signal processor to process the LF signal. The digital signal processor includes a phase detector, a loop filter, and a digitally controlled oscillator. The phase detector compares the LF signal and a reference signal to generate an error signal. The phase detector also determines a state of the digital signal processor, the state being one of a lock state or an out of lock state. Further, the phase detector detects an event that the RF signal is lost and generate a loss signal. The loop filter filters the error signal and generates an error control signal. The digitally controlled oscillator generates the reference signal based on the error control signal, the state, and the loss signal.

Abstract: A device attached to a railcar of a train is provided. The device comprises a radio frequency (RF) transceiver to transmit and receive a RF signal. The device includes a RF modem configured to convert the received RF signal into a low frequency (LF) analog signal. The device includes a digital signal processor to process the LF signal. The digital signal processor includes a phase detector, a loop filter, and a digitally controlled oscillator. The phase detector compares the LF signal and a reference signal to generate an error signal. The phase detector also determines a state of the digital signal processor, the state being one of a lock state or an out of lock state. Further, the phase detector detects an event that the RF signal is lost and generate a loss signal. The loop filter filters the error signal and generates an error control signal. The digitally controlled oscillator generates the reference signal based on the error control signal, the state, and the loss signal.

Abstract: A viewing system for trains that makes real time visual information in the form of images or video of the vicinity of the end of a train available to a locomotive operator or distant user. The system gathers images or video of the vicinity of the end of a train and transmits and displays the images or video to a remote display on a locomotive or at a remote location off the train. The invention also records the images or video such that the images or video can be recalled and used at a later time.

Abstract: A viewing system for trains that makes real time visual information in the form of images or video of the vicinity of the end of a train available to a locomotive operator or distant user. The system gathers images or video of the vicinity of the end of a train and transmits and displays the images or video to a remote display on a locomotive or at a remote location off the train. The invention also records the images or video such that the images or video can be recalled and used at a later time.

Abstract: A novel scanning monochromator uses a PM stepper-motor to directly drive a diffraction grating. By employing interpolated encoder feedback in combination with the PM stepper-motor feedback, a resolution of over 250,000 pulsed steps is available for each revolution of the PM stepper-motor. This translates into more than 20,000 incremental angular-displacement steps over a usable 30° range of dispersion-element rotation. High field accuracy is achieved by a direct PM stepper-driven diffraction grating, and a unique calibration approach based on Wood's anomalies. A plurality of diffracted light beams emerge from the oscillating grating, and these are scanned past a detector for detection, whereby the relative rotation information of the grating can be detected with great accuracy. A number of tolerance-correcting measures are also included to yield an extremely accurate, self-lubricating scanning monochromator that can be economically produced.

Abstract: A novel scanning monochromator uses a PM stepper-motor to directly drive a diffraction grating. By employing interpolated encoder feedback in combination with the PM stepper-motor feedback, a resolution of over 250,000 pulsed steps is available for each revolution of the PM stepper-motor. This translates into more than 20,000 incremental angular-displacement steps over a usable 30° range of dispersion-element rotation. High field accuracy is achieved by a direct PM stepper-driven diffraction grating, and a unique calibration approach based on Wood's anomalies. A plurality of diffracted light beams emerge from the oscillating grating, and these are scanned past a detector for detection, whereby the relative rotation information of the grating can be detected with great accuracy. A number of tolerance-correcting measures are also included to yield an extremely accurate, self-lubricating scanning monochromator that can be economically produced.

Abstract: A novel scanning monochromator uses a PM stepper-motor to directly drive a diffraction grating. By employing interpolated encoder feedback in combination with the PM stepper-motor feedback, a resolution of over 250,000 pulsed steps is available for each revolution of the PM stepper-motor. This translates into more than 20,000 incremental angular-displacement steps over a usable 30° range of dispersion-element rotation. High field accuracy is achieved by a direct PM stepper-driven diffraction grating, and a unique calibration approach based on Wood's anomalies. A plurality of diffracted light beams emerge from the oscillating grating, and these are scanned past a detector for detection, whereby the relative rotation information of the grating can be detected with great accuracy. A number of tolerance-correcting measures are also included to yield an extremely accurate, self-lubricating scanning monochromator that can be economically produced.

Abstract: A method for high speed spectroscopic constituent verification. The method includes the steps of illuminating a sample with broadband light and measuring two preselected wavelengths of reflected light: a first narrow-range of wavelengths &lgr;1 that is not significantly absorbed by the constituent of interest, and a second narrow-range of wavelengths &lgr;2 that is substantially absorbed by the constituent of interest. Given the two measurements of reflection, upper and lower thresholds are determined (the latter based on a percentage of the measured baseline reflected light of wavelengths &lgr;1). Finally, the presence of the constituent of interest is indicated if the measure of the reflected discriminant wavelength &lgr;1 is within the upper and lower threshold measures of reflected baseline light &lgr;1.

Abstract: A modular probe is provided to enable introduction of light to a sample to be analyzed by an electro-optical device. The probe of the present invention may include an optical rod or other device for propagating light, an optical barrel which in part surrounds the optical rod, and a sleeve which is provided to attach the probe to a source of light such as a fiber optical bundle. The probe may be fitted with a bidirectional focusing adapter and a reflective tip. A transverse probe is also described.

Abstract: The invention is a multiplexer which enables light to be sent to and received from samples for simultaneous analysis. A multiplexer is described which uses a transverse probe to reflect light at an angle into an optical rod. The transverse probe is selectively rotated to transmit light to a second optical rod. Various numbers of optical rods may be used in the linear mutliplexer. A multiplexer is also described in which a conjugate optical barrel is utilized to selectively reflect light to various probes.

Abstract: A purge module is provided which provides gas to an enclosure at a first flow rate in order to purge the enclosure of harmful gases. After the pressure within the enclosure has reached a predetermined level, a sensor enables gas at a low pressure to be supplied to the enclosure after a predetermined time has passed. The purge module also enables power to be supplied to the device being purged at the same time the purge gas flow rate is changed.