Abstract: A transmitter in a process control system transmits a pressure over a process control loop. The transmitter includes I/O circuitry, compensation circuitry and an absolute pressure sensor. The I/O circuitry transmits information over the process control loop. Compensation circuitry receives a pressure related signal and responsively control's the I/O circuitry to transmit pressure information on the loop. The absolute pressure sensor includes a cavity which deforms as the sensor deflects in response to an applied pressure. A sensor in the cavity provides the pressure related signal to the compensation circuitry in response to the deformation.

Abstract: To transparently transport an incoming clock signal (CLK2) with a known frequency over a network segment wherein transmission between a transmitter (TX) and a receiver (RX) operates synchronous to a transmit clock signal (CLK1) and receiver clock signal (CLK1') which are synchronized, the transmitter measures the phase difference (P) between the incoming clock signal (CLK2) and a reference signal (R) obtained from the transmit clock signal (CLK1). The measured phase difference (P) is communicated to the receiver (RX) and used therein to generate a copy clock signal (CLK2).

Abstract: A system for tracking a target comprises an acquisition sight used by a pt of an aircraft to acquire and begin tracking the target. Once the pilot acquires the target an operator can use a track handle to track the target. The operator monitors the target utilizing narrow and wide field of view monitors. A computer receives azimuth and elevation data from the tracking device which may be the acquisition sight, track handle, a video tracking system or a tracking radar coupled to an infrared display system. The computer then processes the azimuth and elevation data and provides azimuth and elevation angle signals to a gimbal mirror interface which steers the gimballed mirror to the target. The gimballed mirror receives image forming light from the target and then directs the image forming light to a wide field of view camera and a zoom telescope. The wide field of view camera is connected to the wide field of view monitor to display the target on the wide field of view monitor.

Abstract: A method is disclosed for packaging and collecting PM data generated in PM data modules having current and previous data banks as a source of PM data during a monitoring interval, including the steps of receiving a demarcation signal from a system timer indicating the expiration of the monitoring interval, sending a signal, responsive to the demarcation signal, to the PM data modules instructing each of the modules to swap data banks, reading the PM data located in the previous data bank representing the monitoring interval, optionally packaging the PM data into a single byte stream, sending an armed and ready message to a controller, receiving a request for bulk transfer of the PM data, transmitting the PM data in one bulk transfer to the controller, and resetting the system timer for a next monitoring interval.

Abstract: An explicit rate congestion control system and method to support available bit rate service in asynchronous transfer mode (ATM) networks is provided. The system and method observe the maximum usage of different connections and incorporates both rate and queue length information to achieve a stable operation of the ATM network. The control of congestion and fairness is separated which permits the system and method to have a common framework to support multiple fairness criteria. The system and method may operate with switches implementing both aggregate and per connection queuing at their ports. In the method, the number of active connections at a bottleneck node is only used to normalize control and to redistribute spare bandwidth during transient conditions and does not affect the steady state fair rate used by each connection.

Abstract: A method and system provides connections to an ATM system and includes selective echo cancellation. The system includes two interworking units, an echo canceller, and a signaling processor. The signaling processor receives and processes signaling to provide connection control instructions to the interworking units. The first interworking unit will accept a connection, and if the connection does not require echo cancellation, interwork the incoming connection with an ATM connection to the ATM system. If the incoming connection requires echo cancellation, the first interworking unit will interwork the incoming connection with an ATM connection to the second interworking unit. The second interworking unit will interwork the ATM connection with another connection to echo cancellation. After echo cancellation, the second interworking unit will interwork the connection from echo cancellation with another ATM connection to the ATM system.

Abstract: A method of measuring dynamic air pressure on a ground surface beneath a negative air system which is comprised of a rotatable negative air pressure element with a deck unit having a top with side walls and an open bottom involves placing the system on an elevated horizontal platform located in spaced relation to the deck. The system is then made operative. Measurements are then made of the air pressure at a plurality of locations adjacent the platform to determine if the air pressure at such locations is such that predetermined values are met. The apparatus for performing the aforesaid method has a horizontal platform with a plurality of apertures therein. The platform is adapted to support the negative air system. A plurality of air pressure sensors are mounted in spaced locations on the platform and are located in the lower end of hollow extending tubular pressure taps.

Abstract: A method is disclosed for processing PM signals to be optionally applied to an accumulator PM data module for further analysis including the steps of monitoring first and second transmission line channels to detect events, generating first and second PM signals in response to the events, receiving the first and second PM signals in first and second delay modules, the first and second delay modules having first and second module values therein, and optionally applying, responsive to the second PM signal, the first module values to the accumulator PM data module so as to acquire PM data for collection, storage and analysis.

Abstract: Apparatus is provided for sensing the pressure and temperature of fluid within a cavity of a block, such as hot plastic that flows into a mold cavity. The apparatus includes a piston (30) lying closely but slideably within a bore that extends from the cavity in the block. The outer end of the piston is coupled through a beam structure (36), in a shape of a diaphragm, to a rigid support (40). A strain gauge (44) mounted on the diaphragm senses piston deflection which is proportional to the pressure of fluid in the cavity. A highly heat conductive rod (80) extends through a hole in the middle of the piston, the rod having an inner end (84) that is flush with the piston and the rod having an outer end (86) joined at a thermocouple joint (92), so the temperature of the rod is sensed by the thermocouple to thereby sense the temperature of material in the cavity.

Abstract: A capacitive pressure sensor capsule has a housing with a ceramic cover sealingly attached to a ceramic base that defines an interior chamber. The sensing medium enters the chamber through an inlet port. A glass sensor is attached to an integral pillar that extends from the housing into the chamber. A conducting member extends through the pillar into the housing and carries the signals from the sensor. The combination of the glass sensor and ceramic housing provides high accuracy over a wide range of temperature, because the thermal coefficient of expansion of glass and ceramic are similar. Hermetic sealing of the sensor electrical circuitry ensures long term immunity from the sensed environment.

Abstract: A pressure sensor including a substrate having a diaphragm portion. A diaphragm-defining recess is recessed inwardly from one surface of the substrate to define the diaphragm portion between a bottom surface of the recess and an opposite surface of the substrate. A recess is disposed within the diaphragm portion. A pressure sensitive arrangement is disposed in the substrate, a detector portion of which is disposed within the recess formed within the diaphragm portion.

Abstract: A process control instrument adapted to provide an output indicative of a parameter of a process fluid is disclosed. The process control instrument is designed to be attachable to a flange having a first passageway filled with process fluid. A body of the process control instrument has an opening adjacent to the first passageway adapted to receive process fluid from the first passageway. An isolation diaphragm is positioned in the opening of the body and separates the opening and the first passageway from a second passageway. A weld ring positioned in the opening is adapted to evenly distribute an attachment force across a support surface such that damage to the isolation diaphragm is minimized.

Abstract: An apparatus for testing a tire. The tire has sidewalls and a tread portion. The tread portion has inner and outer surfaces. The apparatus comprises a tire lift. The tire lift has a main frame and a subframe. The subframe engages the main frame and is movable in a vertical direction. First and second drive rollers are operably connected to the subframe and arranged to support the tread portion. A stabilization roller is operably connected to the tire lift. The stabilization roller is arranged and configured to be placed proximal to one of the sidewalls. First and second electrodes are operably connected to the tire lift. The first and second electrodes are arranged and configured to be positioned on opposite sides of the tread portion. A power supply is arranged and configured to create an electrical potential between the first and second electrodes.

Abstract: The pressure sensor component is mountable on the component-mounting surface of a printed circuit board. The component has a chip carrier of electrically insulating material formed with a substantially flat chip carrier surface. A semiconductor chip with a pressure sensor is fastened on the chip carrier surface. Electrode connections with a surface-mountable structure penetrate the chip carrier and they are electrically connected to the semiconductor chip. The chip carrier is filled with a flowable filler completely covering the semiconductor chip.

Abstract: A technique for monitoring anomalies in a railway system 400. The technique uses a motion sensor 207, 209 operably coupled to a chassis of a rail car 101 to detect a possibility of an event which may correspond to an anomaly in the railway system. A global positioning sensor (GPS) 213 operably coupled to the chassis detects a geographical location of the rail car 101 at a time corresponding to the event, which correlates the anomaly to the geographical location and the time. The technique also uses a processor 301 operably coupled to the motion sensor 207, 209 to direct a signal corresponding to the event and a recorder 215 operably coupled to the processor 301 to log the signal which may correspond to the anomaly and the geographical location of the rail car corresponding to the event. A central station 104 tracks and analyzes the anomaly over time to predict a possible defect in the railway system.

Abstract: A pressure sensor is provided which can detect the presence, absence or magnitude of pressure, as well as a pressure profile. The pressure sensor includes a sensor membrane and a sensor device. The sensor membrane is flexible and may be constructed of a conductive material or may include a flexible film attached to a conductive film. The sensor device includes a sensor strip, a voltage source, and an electrical sensor. The sensor strip includes both a conductive strip and a resistive strip. The conductive strip is arranged parallel to the resistive strip. As pressure is applied to the sensor membrane, the sensor membrane distends or deforms towards the sensor strip. As sufficient pressure is applied, the sensor membrane will make both electrical and mechanical contact with both the conductive strip and the resistive strip at a point along the length of the sensor strip. Since the sensor membrane is conductive, the conductive strip and the resistive strip will be in electrical connection with each other.

Abstract: A tire testing device comprising an air pressure control means for changing the tire pressure of a wheel, a test head and a computer, which prior to and after a change in the air pressure produce an interferogram of the tire surface and convert the interferogram into a modulo-2.pi.

Abstract: A circuit and apparatus for generating a light pulse from an inexpensive light-emitting diode (LED) for an accurate distance measurement and ranging instrument comprises an LED and a firing circuit. An optional pre-biasing circuit provides a reverse-bias signal to the LED to ensure the LED does not begin to emit light before a firing circuit can provide a sufficiently high current pulse of short duration as a forward current through the LED. The LED is driven by the firing circuit with a pulse of high peak power and short duration. The resulting light pulse from the LED can be inexpensively used to derive distance and ranging information for use in a distance measurement and ranging device.

Abstract: A gauge or differential pressure sensor has a base portion having walls which define a cavity within the base portion and a diaphragm portion positioned over the cavity. The base portion comprises silicon; the diaphragm portion comprises silicon; the substrate has a passageway from a surface of the substrate into the chamber; the walls of the cavity form an angle with the diaphragm of no more than ninety degrees; and the chamber has a depth of at least about 5 microns. Preferably, the pressure sensor has a lip within the passageway which prevents an adhesive used to glue the sensor to a base from flowing to the diaphragm and fouling it. The pressure sensor is made by forming a cavity in a first wafer, fusion bonding a second wafer over the first wafer in an oxidizing environment, and using the thin oxide formed when fusion bonding the wafers as an etch stop when opening the cavity to the atmosphere. Etch conditions are selected to form the preferred lip in the passageway.

Abstract: A system and method for testing the pressure in a fluid system, according to which a member is provided for connecting to the fluid system in a manner to receive fluid from the system. A hydraulic cylinder establishes a fluid pressure and is connected to the member so that the cylinder can establish a predetermined fluid pressure in the system which is measured by a gauge and monitored.