Abstract: A manipulator for expendable immersion devices is provided with a spring loaded distal end to absorb mechanical shock when the immersion device is mounted on the manipulator and the manipulator is provided with a mechanical stop to eliminate the possibility of mechanical damage to the immersion device.
Abstract: A high speed, high accuracy surface temperature measuring probe of the contact type including a thin-film platinum resistance thermometer mounted in a support assembly having a low specific heat and low conductivity with a thin pure copper end cap in thermal contact with the resistance thermometer and extending along the sidewalls of the probe for a short distance.
Abstract: A communications system with a local network having two metallic cables providing redundant channels between stations of a group with redundant optical rings forming a highway interconnecting those networks. An optical-electrical interface connects the networks and the ring.This interface includes an optical detector producing a corresponding electrical signal, an optical transmitter which repeats the detected message, and a control element connecting the output of the detector with the transmitter. A control signal supplied over one metallic line from the station which is transmitting to its interface causes the control element to disconnect the detector and transmitter to prevent operation of the combination as a repeater. The transmission is then supplied over another metallic line from the station to the transmitter and thence around the ring until it is converted to an electrical signal at the corresponding detector.
Abstract: There is provided a differential amplifier having a plurality of inputs connected through input resistors to a summing junction at the inverting input of a differential amplifier which also has a negative feedback path having a feedback resistor. One of the input resistors is connected to the output signal of the primary element or transducer. A second of the input resistors is connected to a zero compensating signal which varies with changes in the temperature of the transducer from a certain value at a reference temperature. A third input resistor is connected to a fixed signal of a value which is adjusted to correspond to the certain value of the compensating signal at the reference temperature but of opposite polarity so as to tend to cancel the compensating signal when the transducer is at the reference temperature. The combination of the three inputs then produces an output from the differential amplifier corrected for changes in the zero of the measurement due to temperature changes.
Abstract: A refractory protection tube for immersion molten metal parameter determining devices having a thin perforated metal tube with a coating of refractory fibers and a binder to provide thermal insulation, freedom from out-gassing and mechanical strength.
Abstract: A preamplifier for use primarily with a solid state line scanner for amplifying the signal output from the scanner and suppressing the noise from switching spikes featuring a cascode-connected input stage in a preamplifier having its gain stabilized by negative feedback.
Abstract: A portable automatic disappearing filament optical pyrometer having low power demand incorporating a solid state line scanner as a sensing element is controlled by a microprocessor to perform a balance between the radiation from a target and a lamp filament to provide a digital indication of the temperature of the target including compensation for emissivity of the target.
October 16, 1980
Date of Patent:
March 1, 1983
Leeds & Northrup Company
Alexander H. Clark, John E. O'Neil, Albert S. Tenney, III
Abstract: A circuit for preventing data transfers to a RAM by a microprocessor when primary ac power fails also puts the RAM in standby after a period adequate to complete any data transfer started. The sequence is provided by providing a first signal to the microprocessor transfer enable line upon loss of primary power. A second signal is provided for the enable line of the RAM after a predetermined delay but before decay of the dc power to the RAM.
Abstract: A thin film resistance thermometer is manufactured to have a predetermined temperature coefficient of resistance while minimizing the amount of metal in the film. The process involves the production of a metal film deposit on an insulating substrate such that the film deposited has a bulk coefficient substantially higher than the desired coefficient with the film being deposited to a thickness that produces the desired coefficient.
Abstract: A means to change the position of a drive unit in accordance with desired changes periodically provided as a digital value and entered in a first register, which is then decremented to zero by counting actual increments of drive unit change. Power to change the drive unit is proportional to the residual value in this register, with no power when actual change has equalled desired change. The count of actual change increments is determined from clock pulses updating a second register representing position whenever the analog equivalent of this register differs from an analog signal representing actual position.
Abstract: An analog to digital converter of the ramp-integrator type with provisions to reduce errors due to offset voltages. The cycle which is utilized includes a preconditioning cycle during which the capacitor is charged while the input to the buffer amplifier is connected to the datum level voltage, such as ground. A microprocessor is used to compute the unknown signal.
Abstract: A signal compensating network for use with a sensing element having different rates of response for increasing or decreasing sensed quantities includes a differentiating amplifier having different time constants for increasing and decreasing input signals. The output from the differentiating amplifier is combined with a signal representing the magnitude of the input signal to produce an output.
Abstract: A transducer housing assembly for an ultrasonic flowmeter made by an injection molding having a pair of pedestals for supporting the transducers at a specific angle while acoustically isolating the transducers from each other and providing an air backing for the transducers to improve the sensitivity of the transducer assembly.
October 14, 1980
Date of Patent:
June 8, 1982
Leeds & Northrup Company
James G. Connery, Dominick D. Diascro, Louis D. DiNapoli, Giancarlo Punis, Anthony J. Matour
Abstract: A preamplifier circuit for a voltage measuring instrument which provides for noninteracting span and zero adjustments. Two voltage follower circuits are used. The first produces a current through the output resistor of the preamplifier proportional to the voltage being measured while the second produces a current through the output resistor proportional to a fixed reference voltage. For both amplifiers, the proportionality is adjustable by a potentiometer which modifies the feedback on the first amplifier and the part of the reference used as input to the second amplifier.
Abstract: An ultrasonic Doppler flowmeter for measuring flowing fluid by reflection of sonic waves from particles in the fluid is provided with a discriminating circuit including a comparator amplifier connected to the received signal that produces a zero-flow output from the flowmeter when the signal received by the receiving means is produced by vibration of the reflecting particles in a zero-flow condition.
October 10, 1979
Date of Patent:
July 28, 1981
Leeds & Northrup Company
James G. Connery, Louis D. DiNapoli, Giancarlo Punis
Abstract: A boiler control system for boilers fired by solid fuels wherein the fuels are carried through the combustion zone of the boiler on a traveling grate and wherein the air flow for combustion as supplied to the undergrate region utilizes a control of the fuel rate from a deviation of the outlet pressure from the desired value with the control of the air flow to the undergrate region maintained generally in proportion to the steam flow from the boiler with the proportionality being biased from the deviation of the outlet pressure from its desired value.
Abstract: An expendable phase change detector device is provided with an initial coating on the twisted wire forming the thermocouple junction which is, in turn, covered by a refractory coating during the manufacture of the device. The initial coating responds to an increased temperature to ablate the refractory coating from the thermocouple junction when molten metal is poured into the device.
Abstract: A control system is provided for turbines in the utility part of an industrial plant using cogeneration so that control is maintained over the relative quantities of steam supplied to a common steam header from both the back pressure and the extraction turbines where the header supplies process steam at a predetermined pressure. The steam flow from a stage of the extraction turbine is controlled to maintain the header pressure at its desired value. The steam flow thus controlled is measured and a control means is provided to control the steam flow from a back pressure turbine supplying the same header so as to maintain a predetermined relationship between the two steam flows while maintaining electrical generation from the generators driven by the turbine at a maximum consistent with maintenance of an adequate control range for the header pressure control.
Abstract: A time variant measured variable is graphically displayed in moving strip chart format on a cathode ray tube. During a scan line the electron beam is intensity modulated at a position on the scan line whith represents the magnitude of the measured variable at a given time. The intensity of the electron beam at positions in successive scan lines is similarly intensitymodulated to produce a trend line representing the magnitude of the variable along the strip chart format. During the scanning of a subsequent raster frame, a new data value of the measured variable is displayed at a selected position at an edge of the viewing area of the strip chart format in thwe location previously occupied by the next sequential value and the older data values are simultaneously displaced. The oldest data value is deleted from the format. During a raster scan the electron beam is modulated at different intensity levels to produce chart lines and time lines on the strip chart format.