Abstract: Ultrasonic bone testing apparatus including a pair of spaced piezoelectric copolymer transducers for transmitting and receiving ultrasonic energy through a bone-containing portion of a human or other animal disposed between the transducers, and circuitry for detecting an electrical signal generated by the receiving transducer in response to reception of ultrasonic energy. The transducers are disks of the copolymer supported by rigid rings spaced inwardly of their peripheries. A method of determining a characteristic of bone in a bone-containing portion of an animal includes positioning a pair of piezoelectric copolymer ultrasonic transducers respectively on opposite sides of, and ultrasonically coupling both transducers to, the animal portion, and transmitting ultrasonic energy through the animal portion including the bone to be tested from one transducer to the other. The animal portion may be a human heel.

Abstract: Ultrasonic bone testing apparatus including a pair of spaced piezoelectric copolymer transducers for transmitting and receiving ultrasonic energy through a bone-containing portion of a human or other animal disposed between the transducers, and circuitry for detecting an electrical signal generated by the receiving transducer in response to reception of ultrasonic energy. The transducers are disks of the copolymer supported by rigid rings spaced inwardly of their peripheries. A method of determining a characteristic of bone in a bone-containing portion of an animal includes positioning a pair of piezoelectric copolymer ultrasonic transducers respectively on opposite sides of, and ultrasonically coupling both transducers to, the animal portion, and transmitting ultrasonic energy through the animal portion including the bone to be tested from one transducer to the other. The animal portion may be a human heel.

Abstract: An x-ray detector includes a solid scintillating crystal of cadmium tungstate or bismuth germanate; the crystal is mounted in an x-radiation field and includes a first region directly exposed to the x-radiation. A protective shield is arranged adjacent the crystal so as to protect a region in space from direct exposure to x-radiation. The crystal includes a second component which is located in the protected region of space and is thus not exposed to direct x-radiation. Located in contact with opposing faces of the crystal are two pairs of photodiodes, the photodiodes themselves as well as the crystal faces with which they are in contact lie in the protected region in space and therefore are not exposed to direct x-radiation. The photodiodes themselves are also protected from scattered x-radiation by the protected component of the crystal. One pair of photodiodes has equal active areas, which is however different from the active areas of the other pair of photodiodes.

Abstract: A method and apparatus for detecting and measuring radiation is disclosed. The apparatus includes a scintillator crystal and a photodetector optically coupled to the scintillator crystal as well as first and second analyzing means. The first analyzing means is coupled to an output of the photodetector for counting discrete electronic pulses generated by the photodetector. The second analyzing means operates simultaneous with the first analyzing means and is coupled to another output of the photodetector for integrating current generated by the photodetector. The method includes the steps of irradiating a scintillator with x-ray energy, detecting light emitted from the scintillator and converting the light into a flow of electrons, detecting and counting discrete pulses of the flow of electronics and simultaneously integrating electronic current corresponding to the flow of electrons.

Abstract: A remote load controlling apparatus receives a disconnect signal on a line that is filtered and voltage limited. This disconnect signal sets a flip-flop which enables an oscillator and a solid-state switch. The enabled switch energizes a relay to disconnect the load from electric service. A counter counts the output of the enabled oscillator and provides a flip-flop reset signal after a local time delay that is determined by a particular incremented count state of the counter. The reset flip-flop disables the oscillator and solid-state switch to de-energize the relay and reconnect the load to electric service. The flip-flop may also be reset by a remote signal to disable the oscillator and solid-state switch and reconnect the load before the counter is incremented to its particular incremented count state. A second counter and a second solid-state switch may be added to ensure that the load is connected to electric service if a component of the apparatus should fail.

Abstract: A remote meter-reading system interrogates meter stations over power lines and receives encoded meter readings over the power lines in synchronism with the power line frequency by superimposing a digitally modulated signal over the 60-Hz power frequency. The central control station transmits at a data rate of 60-baud and receives at a data rate that is 60-baud or a submultiple thereof, to reduce the demands on the remote meter station transceiver as compared to those on the central control unit transceiver. The bit clock at the central control unit and the meter stations is derived from the 60-Hz power line phase available at each station. Each meter station achieves message synchronization by continuously monitoring the data bit stream for a preset synchronization code and thereafter treats the following 21 data bits as address and function codes.