Abstract: An instrument for measuring a physical quantity, an instrument system having a plurality of such instruments, and a method for operating such a system are described. The instrument includes a sensor, an instrument class error calculator and a communication interface. The sensor measures the physical quantity and generates a value, Vm, for the physical quantity. The instrument class error calculator provides an instrument class error associated with Vm. The instrument system includes a plurality of these instruments that are manufactured on an ongoing basis. The instrument system includes a database that stores a measurement generated by each instrument in a sample of the instruments during manufacture and a communication link between the database and one of the instruments in the class that provides information on the instruments based on measurements made after the one of the instruments in the class was manufactured.

Abstract: A hybrid LiDAR-imaging device is configured for aerial surveying and comprises a camera arrangement adapted for generating orthophoto data and a LiDAR device, in which an overall exposure area is provided by the camera arrangement, which has a transverse extension of at least 60 mm and the LiDAR device has a longitudinal extension axially along a ground viewing nominal LiDAR axis and a lateral extension substantially orthogonal to the nominal LiDAR axis, in which the longitudinal extension is larger than the lateral extension.

Abstract: Concrete can be one of the most durable building materials and structures made of concrete can have a long service life. Consumption is projected to reach approximately 40 billion tons in 2017. Despite this the testing of concrete at all stages of its life cycle is still in its early stages although testing for corrosion is well established. Further many of the tests today are time consuming, expensive, and provide results only after it has been poured and set. Embodiments of the invention provide concrete suppliers, construction companies, regulators, architects, and others with rapid testing and performance data regarding the cure, performance, corrosion of concrete at different points in its life cycle based upon a simple electrical tests that remove subjectivity, allow for rapid assessment, are integrable to the construction process, and provided full life cycle assessment. Wireless sensors can be embedded from initial loading through post-cure into service life.

Abstract: Disclosed herein are systems and methods for enabling at least one autonomous device to traverse a three-dimensional space. An example system may comprise a first autonomous vehicle comprising a first sensor suite. The first autonomous vehicle may traverse the three-dimensional space in accordance with a path planned vector. The path planned vector may be dynamically updated based on a first vector associated with a first object identified based on data received from the first sensor suite. The example system may comprise a first aerial vehicle comprising a second sensor suite. The first aerial vehicle may traverse the three-dimensional space based on at least one of data provided by the second sensor suite, the first sensor suite, and other aerial vehicles. The path planned vector may be dynamically updated based on data received from at least one of the first sensor suite, the second sensor suite, and cloud interface data.

Abstract: The present disclosure includes circuits and methods for controlling the operation of a switching regulator. In one embodiment, the present disclosure includes a circuit comprising a switching regulator with a current control loop comprising a capacitor configured to store a first voltage during a first phase and configured to boost a voltage produced by an output current through a low side switching device by the first voltage in a second phase. Circuitry compares the boosted voltage to a control voltage produced by a control current through a replica device corresponding to the low side switching device.

Abstract: An accurate, cost-efficient temperature sensor may be integrated into an integrated circuit (IC) using common materials as the IC's interconnect metallization. The temperature sensor may include an impedance element having a length of metal made of the interconnect metal, a current source connected between a first set of contacts at opposite ends of the impedance element, and an analog-to-digital converter connected between a second set of contacts at opposite ends of the impedance element. The temperature sensor may exploits the proportional relationship between the metal's resistance and temperature to measure ambient temperature. Alternatively, such a temperature sensor may be used on disposable chemical sensors where the impedance element is made of a common metal as conductors that connect a sensor reactant to sensor contacts. In either case, because the impedance element is formed of a common metal as other interconnect, it is expected to incur low manufacturing costs.

Abstract: Meter electronics (20) for quantifying a fluid being transferred is provided. The meter electronics (20) includes an interface (201) configured to communicate with a flowmeter assembly of a vibratory flowmeter and receive a vibrational response and a processing system (203) coupled to the interface (201). The processing system (203) is configured to measure a mass flow and a density for a predetermined time portion of the fluid transfer, determine if the fluid transfer is non-aerated during the predetermined time portion, if the predetermined time portion is non-aerated then add a mass-density product to an accumulated mass-density product and add the mass flow to an accumulated mass flow, and determine a non-aerated mass-weighted density for the fluid transfer by dividing the accumulated mass-density product by the accumulated mass flow.

Abstract: A container data center includes a cooling control system. The cooling control system reads a temperature of a container of the container data center and a direction of wind flowing across the container, and determines whether a first or a second cooling device of the container data center needs to be turned on according to the read temperature. The cooling control system further determines whether the read wind direction is the same to a direction of hot air expelled by the turned on cooling device. When the read wind direction is not the same as a direction of hot air expelled by the turned on cooling device, the cooling control system turns off the turned on cooling device, and turns on the other cooling device.

Abstract: An electronic thermistor-based vacuum gauge and systems and methods of calibration and operation of the same that require no calibration against a known vacuum standard to obtain high accuracy through broad vacuum and ambient temperature ranges. Additional features of the invention include a construction and method of improving battery life, a construction and method of detecting faulty vacuum sensors, a method for determining the state of calibration of a vacuum sensor, a method of quantifying vacuum leak rates, and a method of automatically alerting an operator when an evacuation process has concluded.

Abstract: A method, device and system are provided for measuring multiple pressures under severe conditions. In one embodiment, a method comprises receiving, by a processor, from a first sensor, a first pressure signal; receiving, by the processor, from a second sensor, a second pressure signal; receiving, by the processor, from a first memory, a first correction coefficient for the first sensor; receiving, by the processor, from a second memory, a second correction coefficient for the second sensor; modifying, by the processor, the first pressure signal using the first correction coefficient to generate a first corrected pressure signal; modifying, by the processor, the second pressure signal using the second correction coefficient to generate a second corrected pressure signal; and outputting, by the processor, the first corrected pressure signal and the second corrected pressure signal.

Abstract: Systems and methods for determining spatially dense dynamic properties of a structure are disclosed. In particular, spatially dense mode shapes are determined using acceleration records collected when one or several sensors are moving. The mobile sensor gathers vibration response data for the structure as the mobile sensor moves over the structure. The vibration response data is used to extract a fine grid of modal coordinates with a reduced number of sensors and without requiring mode shape expansion. The high spatially dense mode shapes can be included as part of accurate numerical models for the structure that can be used for a variety of purposes, such as damage detection, earthquake engineering, wind engineering, and other suitable purposes.

Abstract: An electronic thermistor-based vacuum gauge and systems and methods of calibration and operation of the same that require no calibration against a known vacuum standard to obtain high accuracy through broad vacuum and ambient temperature ranges. Additional features of the invention include a construction and method of improving battery life, a construction and method of detecting faulty vacuum sensors, a method for determining the state of calibration of a vacuum sensor, a method of quantifying vacuum leak rates, and a method of automatically alerting an operator when an evacuation process has concluded.

Abstract: The present invention provides a method of on-line rapid fluid density measurement using a piezoresistive micro-cantilever, the present invention can achieve on-line measurement without changing the existing device; more importantly, without acquiring the resonant frequency of the cantilever in fluid to be detected, thus remarkably reducing measurement time, and guaranteeing the real on-line rapid measurement. By using the method of the present invention, measurement of the density of fluid to be detected by a calibrated piezoresistive micro-cantilever may be achieved within seconds or even shorter.

Abstract: An electronic thermistor-based vacuum gauge and systems and methods of calibration and operation of the same that require no calibration against a known vacuum standard to obtain high accuracy through broad vacuum and ambient temperature ranges. Additional features of the invention include a construction and method of improving battery life, a construction and method of detecting faulty vacuum sensors, a method for determining the state of calibration of a vacuum sensor, a method of quantifying vacuum leak rates, and a method of automatically alerting an operator when an evacuation process has concluded.

Abstract: A process for testing an integrated circuit includes collecting a set of points of a physical property while the integrated circuit is executing a multiplication, dividing the set of points into a plurality subsets of lateral points, calculating an estimation of the value of the physical property for each subset, and applying to the subset of lateral points a step of horizontal transversal statistical processing by using the estimations of the value of the physical property, to verify a hypothesis about the variables manipulated by the integrated circuit.

Abstract: A ground fault detection system is provided. The ground fault detection system includes a magnetic core having first and second primary legs and a secondary leg disposed between the first and second primary legs. The ground fault detection system also includes first and second primary windings disposed around the first and second primary legs respectively and configured to introduce current in the first and second primary legs. Further, the ground fault detection system includes first and second secondary windings disposed around the first and second primary legs respectively and configured to detect a ground fault based upon a magnetic flux generated in response to the introduced current.

Abstract: A system and method of monitoring oil consumption in a gas turbine engine system are provided. When the gas turbine engine is not running the reservoir oil level, reservoir oil temperature, and reservoir attitude are sensed. The current gas turbine engine system oil quantity is determined based on at least the sensed reservoir oil level, the sensed reservoir oil temperature, and the sensed reservoir attitude. When a predetermined event has occurred, an average gas turbine engine system oil quantity is automatically calculated. The gas turbine engine system oil consumption rate is determined from a plurality of the average oil quantities.

Abstract: An underwater depth measurement device includes a piezoresistive ceramic transducer in communication with a circuit for outputting an absolute pressure.

Abstract: A method and apparatus are provided for detecting and transmitting geophysical data from a plurality of electrodes inserted into the soil utilizing a set of identical dynamically reconfigurable voltage control units located on each electrode and connected together by a communications and power cable. A test sequence is provided in each voltage control unit. Each voltage control unit records data measurements for transmission to a central data collector. Each voltage control unit incorporates and determines its positional relationship to other voltage control units by logging when the unit is attached to the electrode. Each voltage control unit I equipped with a magnetic switch for detecting when they are in contact with the electrode.

Abstract: A melt pressure sensor comprises a housing, a stem, a pressure sensing element, a time-to-digital converter, a processor, a digital-to-analog converter, and a first input. The stem comprises a pressure sensing surface fluidly coupled to a molten material. The pressure sensing surface is mechanically or fluidly coupled to the pressure sensing element, and the pressure sensing element is electrically coupled to the time-to-digital converter, which determines the melt pressure by measuring an electrical characteristic of the pressure sensing element. The processor reads the pressure from the time-to-digital converter and outputs an analog output value from the digital-to-analog converter representative of the melt pressure. When the first input is activated, the processor causes the analog output signal to have a predetermined value.

Abstract: A system and method of characterizing or controlling a flow of a fluid is provided that involves a sensor conduit and a bypass. A plurality of fluids may be utilized in the flow control device based on characteristic information of the device generated during calibration thereof. The characteristic information, in turn is based on a dimensionless parameters, such as adjusted dynamic pressure and adjusted Reynolds number.

Abstract: An electronic thermistor-based vacuum gauge and systems and methods of calibration and operation of the same that require no calibration against a known vacuum standard to obtain high accuracy through broad vacuum and ambient temperature ranges. Additional features of the invention include a construction and method of improving battery life, a construction and method of detecting faulty vacuum sensors, a method for determining the state of calibration of a vacuum sensor, a method of quantifying vacuum leak rates, and a method of automatically alerting an operator when an evacuation process has concluded.

Abstract: Methods and apparatus are provided for receiving, detecting and transmitting geophysical data from a plurality of electrodes placed in the soil utilizing a dynamically reconfigurable wireless control unit that is located on each electrode. Data from the control units is transmitted by a wireless signal to a centralized data processor for analysis. Control data is provided from a central control processor to the control unit by wireless transmission. The control unit, which is positioned, includes a multi-channel radio frequency transmitter/receiver and a processor to actuate relays and record data returns from the measured substrate soil for transmission to the central data processor. The control unit incorporates a changeable code or address to unambiguously identify itself, and its spatial relationship to other electrodes, to the central data processor and the central control processor.

Abstract: A system and method of characterizing or controlling a flow of a fluid is provided that involves a sensor conduit and a bypass. A plurality of fluids may be utilized in the flow control device based on characteristic information of the device generated during calibration thereof. The characteristic information, in turn is based on a dimensionless parameters, such as adjusted dynamic pressure and adjusted Reynolds number.

Abstract: For example, to adjust an offset of a pressure sensor, there are provided an external resistor RE and an internal resistor circuit that is connected to both ends of RE and formed in a semiconductor chip such as a processor. The internal resistor circuit includes N pieces of internal resistors RI connected in series between both ends of RE, and (N+1) pieces of switches selecting one of voltages of respective nodes of the serial resistors and outputs the same as a signal. RE has a high absolute value precision of, e.g., several ten ohms to several hundred ohms, and RI has a high relative value precision of, e.g., several kilo-ohms. Therefore, an offset adjustment range is decided at a high absolute value precision mainly by RE, and with regard to the arrangement resolution, a high precision can be obtained along with the relative value precision of the RI.

Abstract: There is disclosed a high temperature pressure sensing system which includes a SOI Wheatstone bridge including piezoresistors. The bridge provides an output which is applied to an analog to digital converter also fabricated using SOI technology. The output of the analog to digital converter is applied to microprocessor, which microprocessor processes the data or output of the bridge to produce a digital output indicative of bridge value. The microprocessor also receives an output from another analog to digital converter indicative of the temperature of the bridge as monitored by a span resistor coupled to the bridge. The microprocessor has a separate memory coupled thereto which is also fabricated from SOI technology and which memory stores various data indicative of the microprocessor also enabling the microprocessor test and system test to be performed.

Abstract: An underwater depth measurement device includes a piezoresistive ceramic transducer in communication with a circuit for outputting an absolute pressure.

Abstract: A system for measuring a multiplicity of pressures as those experienced by a model in a wind tunnel is depicted. The system includes individual sensor devices which are connected to an Acquisition and Compensation electronics module. The individual sensor or transducer devices are semiconductor piezoresistive devices and are connected to the Acquisition and Compensation electronics module by means of a cable in a first embodiment. In an alternate embodiment the system uses connectors which connect each of the individual sensor devices to the Acquisition and Compensation electronics module via a mating connector located therein. The connectors may also include a memory which stores compensation coefficients associated with each of the various sensor devices. In this manner as described, the transducers which are small devices are connected via electrical lines or cables to the central Acquisition and Compensation electronics modules.

Abstract: A method for determining a preferred operating gradient for use in attaining a life objective for an electrical energy storage device in a hybrid vehicle is disclosed. A present state-of-life of the electrical energy storage device is provided and a life target for the electrical energy storage device is established as a predetermined limit in a predetermined metric at a predetermined state-of-life of the electrical energy storage device. A state-of-life gradient is then determined with respect to the predetermined metric which converges the state-of-life of the electrical energy storage device to the life target.

Abstract: There is disclosed a high temperature pressure sensing system which includes a SOI Wheatstone bridge including piezoresistors. The bridge provides an output which is applied to an analog to digital converter also fabricated using SOI technology. The output of the analog to digital converter is applied to microprocessor, which microprocessor processes the data or output of the bridge to produce a digital output indicative of bridge value. The microprocessor also receives an output from another analog to digital converter indicative of the temperature of the bridge as monitored by a span resistor coupled to the bridge. The microprocessor has a separate memory coupled thereto which is also fabricated from SOI technology and which memory stores various data indicative of the microprocessor also enabling the microprocessor test and system test to be performed.

Abstract: A glow plug degradation determination device energizes a glow plug immediately after an operation of an internal combustion engine is stopped. When a preset energization time elapses, the device senses a sensing value corresponding to resistance of the glow plug. The device determines degradation of the glow plug based on the sensing value. When the device determines that the glow plug is degraded, the device stores a result of the determination and reports the degradation of the glow plug before a next start. The device provisionally determines the degradation of the glow plug based on the sensing value during the operation of the internal combustion engine. After the device provisionally determines the degradation to be present, the device determines the degradation of the glow plug immediately after the operation of the internal combustion engine is stopped.

Abstract: A method for evaluating uncertainty associated with the value of a measurand derived from measurements of a device under test is disclosed. A mathematical model is provided wherein the measurand is expressed as a function of (i) at least one physically observable quantity, and (ii) the reference value of the physically observable quantity in a reference device. The reference value of the reference device and the value of the measurand of the device under test are measured. The value of the at least one physically observable quantity is also measured. At least one uncertainty value is determined as a function of the physically observable, wherein the mathematical model takes into account the at least one source of uncertainty and the reference value of the reference device.

Abstract: This device is a wireless tool qualifier that verifies that the correct number of fasteners have been properly installed into an assembly. When used in conjunction with a wireless tool, proper fastener torque and count can be verified. In another embodiment, the wireless qualifier is used with a tool having a self-contained internal power supply (battery). The qualifier is configured to wake up and come out of its low-current sleep state when a conditioned signal is greater than a reference signal. The qualifier is configured to monitor the tool when the tool is awake.

Abstract: A temperature compensating fluid flow sensing system is provided that comprises a resistance-based sensor element that is included in a constant voltage anemometer circuit configured to establish and maintain a command voltage across the first sensor element and to provide a constant voltage anemometer (CVA) output voltage corresponding to the resistance change in the first sensor element due to heat transfer between the first sensor element and the fluid. A controller is configured to establish the command voltage based on a desired overheat across the sensor and an actual overheat across the first sensor element. A power dissipation (PDR) module is configured to determine at least one fluid flow parameter and an actual overheat value based at least in part on the CVA output voltage and to transmit to the controller the actual overheat for use by the controller in updating the command voltage.

Abstract: A system for sensing environmental conditions on a window assembly. The system includes a transparent panel and a sensor integrated onto the panel. The sensor being configured to sense environmental changes on the panel. The sensor may comprise conductive inks that are printed onto the window assembly. The window assembly may comprise a plastic panel, such as a multilayer polycarbonate panel such that a portion of the sensor may be located on the one layer of the panel while another portion of the sensor overlaps the first portion on a second layer of the window. The sensor may be a resistive or capacitive sensor and may be configured to detect changes in one or more environmental conditions, such as temperature or moisture. Further, the sensor may be in electrical communication with a controller configured for control various vehicle subsystems based on the sensor.

Abstract: To enable a trouble diagnosis of braking-input-side pressure sensors even in a state where a braking input side and a braking output side are interrupted from each other. In a brake device of a vehicle in which a braking input side which generates a liquid pressure by manipulating a brake manipulation portion and a braking output side which supplies the liquid pressure to a brake caliper are made to be communicated with each other or being interrupted from each other by way of a first electromagnetic open/close valve, and the brake device includes a hydraulic modulator which adjusts the liquid pressure of the braking output side by operating an electrically-operated motor, the brake device includes a first pressure sensor and a second pressure sensor for detecting the liquid pressure of the braking input side, and a trouble diagnosis of the pressure sensors is performed in response to detection values of the pressure sensors.

Abstract: A method of determining a temperature and a pressure in a tank is provided. The method comprises the steps of obtaining sensor data and calculating coefficients. Then, a bridge resistance is ratiometrically determined from a bridge voltage. A temperature is calculated with the coefficients and the bridge resistance. Thereafter, a transition from a temperature measurement mode to a pressure measurement mode is made. A voltage per resistance is calculated with the coefficients and a differential voltage. Then, a normalized voltage is calculated using the voltage per resistance, the differential voltage, and the bridge resistance to indirectly compensating for temperature. A pressure is calculated with the coefficients and the normalized voltage.

Abstract: A method of evaluating uncertainty associated with the value of a measurand derived from measurements of a device under test comprising providing a mathematical model wherein the measurand is expressed as a function of (i) at least one physically observable quantity, and (ii) the reference value of said physically observable quantity in a reference device; measuring the reference value of the reference device and the value of the measurand of the device under test; measuring the value of said at least one physically observable quantity; and determining at least one uncertainty value as a function of said physically observable quantity from said mathematical model, wherein the mathematical model takes into account the at least one source of uncertainty and the reference value of the reference device.

Abstract: The present invention relates to a fluid metering apparatus, which includes a fluid container and a metering device. The container has a hollow part for storing fluid and the metering device includes electrical metering means and data processing means. The electrical metering means detects change of a physical quantity of the fluid in the container, and the characteristic is expressed with an electrical mode. The data processing means treats the electrical information obtained by the electrical metering means, and converts the electrical information into a physical characteristic of the fluid. The electrical metering means includes a metering component, which provides a strip line component. Moreover, the electrical information is an electrical signal selected from a capacitance value, an inductance value or an impedance value of the strip line component or a combination of the preceding values.

Abstract: A method and apparatus for performing wide area terrain mapping. The system comprises a digital elevation map (DEM) and mosaic generation engine that processes images that are simultaneously captured by an electro-optical camera (RGB camera) and a LIDAR sensor. The image data collected by both the camera and the LIDAR sensor are processed to create a geometrically accurate three-dimensional view of objects viewed from an aerial platform.

Abstract: Methods and apparatus using time domain reflectometry to determine electrical properties of concrete for calculating physical and mechanical properties of the concrete that are indicative of concrete quality and durability. The dielectric constant of a concrete is determined to calculate the gravimetric water content of the concrete for use in finding the water-cement ratio of the concrete. Electrical conductivity of curing concrete is determined to calculate compressive strength of the concrete for use in predicting strength development in the concrete.

Abstract: A temperature and pressure measuring circuit is provided. The circuit comprises an uncompensated pressure transducer, an analog-to-digital converter, a reference resistive device, and first and second switches. The transducer has variable resistive devices between first, second, third, and fourth bridge nodes. The analog-to-digital converter has first and second reference inputs and first and second differential inputs. When the first switch couples the first differential input and the third bridge node and the second switch couples the second differential input and a ground, a bridge voltage is measurable and a bridge resistance is ratiometrically determinable. The bridge resistance is employed to calculate a temperature. When the first switch couples the first differential input and the first bridge node and the second switch couples the second differential input and the second bridge node, a differential voltage is measurable. The differential voltage is employed to calculate a pressure.

Abstract: A process for curing a moldable compound under a plurality of curing conditions by: (1) obtaining time dependent data streams of dielectric or impedance values from a plurality of sensors distributed within a curing mold, wherein the moldable compound is a dialectric for each of the sensors; (2) determining impedance related measurements from the data streams for the plurality of sensors; (3) determining predictive and/or corrective curing actions for enhancing the curing process using the impedance related measurements for the plurality of sensors; and (4) controlling the mass production curing of parts to obtain cured parts having one or more desired properties.

Abstract: The process measuring device includes a flow sensor having a measuring tube, a sensor arrangement for producing a measurement signal, and an evaluation and operating circuit. The method serves to compensate for the effects of interfering potentials which are caused especially by foreign particles or air bubbles in the liquid to be measured. For this purpose, an anomaly in the waveform of the measurement signal caused at least in part by an electrical, especially pulse-shaped, interfering potential is detected by determining within a stored first data set a data group which digitally represents the anomaly. To generate an interference-free data set, the data belonging to the data group are removed from the stored first data set.

Abstract: A method for locating two dimensional critical flow features on a surface of a three dimensional body immersed in a fluid stream is presented. The method includes applying a hot film sensor array on the surface of the body. The hot film sensor array includes a plurality of hot film sensor elements disposable in a two dimensional array over at least a portion of the body surface. Each sensor element is connected to an associated anemometer circuit to provide an output voltage. The method further comprises obtaining output voltage data for each hot film sensor element with the body immersed in the fluid stream under a set of flow conditions and processing the hot film sensor element output voltage data to locate at least one two dimensional critical flow feature on the body surface.

Abstract: A thermal type air flowmeter arranges a temperature-dependent heating resistance element in an air flow path and measures the air flow rate from the output of a gauge circuit containing the heating resistance element. A calculation circuit in the flowmeter is provided for correcting the output characteristic by a polynomial expression higher than a quadratic expression. Thereby, high flowmeter measuring accuracy is achieved in lieu of laser trimming and with small-scale circuit composition.

Abstract: A control system for a gas sensor element capable of lessening the effect of variations in sensor properties among gas sensor elements as well as the effect of environmental factors, such as temperature and humidity, to thereby accurately detect variation in the concentration of a specific gas. In a control system 10 for a gas sensor element 11 whose sensor resistance Rs varies with the concentration of NOx gas, a pulse signal Sc which alternates between 0 V and +5 V is input to a pulse input terminal 17. When a voltage of 5 V is applied to the pulse input terminal 17, a capacitor 14 is charged via a fixed resistor 15 having a resistance Rc and a diode 16. When a voltage of 0 V is applied, the capacitor 14 discharges via the gas sensor element 11. An output voltage Vout is A/D-converted and processed by means of a microcomputer 20, thereby controlling an electronic control assembly 21.

Abstract: A process fluid temperature transmitter includes circuitry that improves compensation of error due to the presence of one or more non-associated voltage sources in a resistance temperature device (RTD) circuit. A method of compensating for such error is also provided.

Abstract: A method for operating a computer to determine the electrical characteristics of a passive planar structure. The method starts by defining a first mesh on the structure. The first mesh divides the structure into polygons. A surface current is defined in the structure as a first weighted sum of a first set of basis functions. The weights of the first basis functions in the first weighted sum are calculated by solving Maxwell's equations. The mesh is then refined by dividing each polygon into a plurality of sub-polygons. The surface current in the sub-polygons is defined as a second weighted sum of a second set of basis functions. The second set of basis functions includes the first set of basis functions and a plurality of extension basis functions representing the additional degrees of freedom introduced by the refined mesh.

Abstract: A fault protective device (48) for limiting the maximum current and voltage applicable to electronic components and wiring (26, 30) located in the fuel tank (10) of an aircraft. Particularly, a fuel gauging system circuit (18) extends from a generator (20) located outside the tank to at least one probe (14) located in the tank and from the probe to instrumentation (24) outside the tank. The device is electrically coupled to the circuit at the tank wall (28) and includes a voltage clamp (50) and series inductor-capacitor resonant circuit (46), so that the resonant circuit provides a low series impedance when applied with a signal at the operating frequency of the input signal applied by the generator but provides a high series impedance when experiencing a signal of a different frequency indicative of a system fault.