Abstract: Test apparatus for a high voltage cable installation includes a high AC voltage source having the frequency range intended to be carried by the cable installation and a high DC voltage source. A switch alternately passes positive and negative polarities of the DC voltage, and the AC voltage source and the alternating polarity DC voltage output from the switch are coupled while isolating the voltage sources from each other. The resulting alternating polarity DC-biased AC voltage is injected into the cable installation to produce indications of incipient faults.

Abstract: A method and apparatus for locating an incipient fault at a point along the length of an insulated power line includes the application of an excitation voltage at an open end of the power line, and the signal pulse transmitted along the power line to the open end is passed through a high pass filter to remove the portion of the signal which is at a frequency below the excitation voltage and its harmonics. The filtered signal is amplified and passed through a band pass filter to remove a high frequency portion of the signal containing a large proportion of noise relative to the frequency of the partial discharge frequency from the incipient fault. This filtered signal is passed to a digital storage device adapted to be triggered by a signal of a predetermined amplitude, and the triggered digital storage device receives the amplified signal directly from the amplifier and stores digital data concerning amplitude and time for the peaks of the amplified signal for a predetermined period of time.

Abstract: An optically based apparatus for non-invasively determining the concentration of optically active substances in a specimen comprises, a source of a beam of spatially coherent light which is acted upon to produce a rotating linear polarized vector therein. A beam splitter splits the beam into a reference beam and a detector beam for passage through the specimen. The detector beam is received upon exiting the specimen and compared with the reference beam to determine the amount of phase shift produced by passage through the specimen. This amount of phase shift is converted into concentration of the optically active substance in the specimen.

Abstract: Apparatus for monitoring respiratory and/or convulsive movements includes a closed loop phase lock system which measures changes in the air path length of continuous wave ultrasound transmitted to and reflected from (the chest/abdomen area of) a subject, and provides an output change signal proportional to changes in air path length caused by respiratory effort of the subject. A window/alarm circuit receives the change signal and triggers an alarm if the change signal remains below a preset lower threshold for a selected time interval, as occurs in apnea. An upper threshold may be set and an alarm triggered if the change signal exceeds the upper threshold for a selected time interval, as occurs in the case of convulsions. The apparatus includes means to provide a signal which follows movement of the subject in an unambiguous manner and which will not trigger an alarm due to extraneous (non-subject) movement.

Abstract: A method and apparatus for locating an incipient fault at a point along the length of an insulated power line includes the application of an excitation voltage at an open end of the power line, and the signal pulse transmitted along the power line to the open end is passed through a high pass filter to remove the portion of the signal which is at a frequency below the excitation voltage and its harmonics. The filtered signal is amplified and passed through a band pass filter to remove a high frequency portion of the signal containing a large proportion of noise relative to the frequency of the partial discharge frequency from the incipient fault. This filtered signal is passed to a digital storage device adapted to be triggered by a signal of a predetermined amplitude, and the triggered digital storage device receives the amplified signal directly from the amplifier and stores digital data concerning amplitude and time for the peaks of the amplified signal for a predetermined period of time.