Abstract: An apparatus for measuring a parameter of a fluid passing through a pipe includes a spatial array of at least two sensors disposed at different axial locations along the pipe. Each of the sensors provides a signal indicative of unsteady pressure within the pipe at a corresponding axial location of the pipe. A signal processor constructs at least a portion of a k-? plot using the signals and detects at least one ridge in the k-? plot. A slope of the at least one ridge is indicative of the parameter of the fluid. The signal processor determines a quality metric by comparing an accumulated energy (power) of k-? pairs along the at least one ridge with an accumulated energy (power) of k-? pairs along at least one ray extending in the k-? plot. The quality metric is indicative of a quality of the at least one ridge.

Abstract: A detection method of reducing the air pressure of tires based on the rotational speed of wheels mounted on a vehicle. The method includes steps of: determining the rotational speed of each wheel, memorizing the rotational speed of each wheel, determining the loading sensitivity of the dynamic load radius of tires caused by movement of a load during turning, comparing said loading sensitivity with the loading sensitivity of the dynamic load radii of tires at initialization which are preliminarily memorized, and judging decompression of tires based on the result of the comparison. Further, a loading sensitivity-calculating method of determining the loading sensitivity of the dynamic load radii of tires includes steps of: determining a lateral acceleration during turning of a vehicle, determining the shift rate of a judgment value which is the relative comparison of rotational speed of wheels on a pair of diagonals of a vehicle, and determining the loading sensitivity.

Abstract: The preferred embodiment of the present invention comprises a single microprocessor-based interface that connects between a noninvasive blood pressure (NIBP) sensor and an invasive blood pressure (IBP) monitor or module. The interface effectively emulates an IBP transducer in such a way that the IBP monitor sees the interface as if it were a regular IBP transducer from a fluid-filled blood pressure monitoring line. It receives the signal from an NIBP sensor and determines the blood pressure corresponding to the signal. It accepts the excitation voltage provided by the IBP monitor. From the excitation voltage and a known transducer sensitivity which the IBP monitor is configured to work with, the interface emulates the IBP transducer output signal corresponding to the blood pressure. The interface also emulates the input and output impedances of the IBP transducer which the IBP monitor is configured to work with.

Abstract: The cubic equations of state (CEOS) relate pressure, temperature and molar volume of a mixture. The deviation of the physical properties of a mixture from ideality is expressed by the compressibility factor. The compressibility factor is calculated from the CEOS. There is described a solution to the CEOS which provides a continuous solution for compressibility factors over the entire range of operating conditions. This solution avoids the non-unique roots, trivial roots and singularities that are present in the prior art solutions of the CEOS.

Abstract: The invention relates to a method and an arrangement for measuring a liquid flow in connection with a pump system. The invention is preferably implemented in a pump system where the pump (240) is driven by an alternating-current motor (230), whose rotating speed is controlled by a control unit (220), such as a frequency converter, for instance. In accordance with the invention, the flow is determined without any direct flow measurement by utilizing characteristic data of the pump and parameters that can be easily and reliably measured. Such parameters comprise the rotation speed of the pump, the liquid pressure and/or the motor power. Both the motor power and the rotation speed can be measured i.a. at the frequency converter (220). In addition, the static liquid pressure can be measured by means of a straightforward and reliable pressure sensor (244, 245), which can be integrated in the pump system.

Abstract: Calibration of a sensor circuit that includes a sensor, a temperature measurement circuit and a signal processing path. The sensor senses a physical parameter to be measured and generates an electrical sensor output signal representing the physical parameter. The temperature measurement circuit outputs a measured temperature. The signal processing path is coupled to the sensor so as to receive the electrical sensor output signal and use the measured temperature to compensate for temperature variations in the electrical sensor output signal. During calibration, the output voltage of the signal processing path is measured at multiple temperatures, and at multiple values of the physical parameter being measured at each temperature while the signal processing path is disconnected from using the measured temperature of the temperature measurement circuit.

Abstract: A field instrument and system for obtaining pressure, flow and temperature data from a facility. The field instrument includes an enclosure having an opening therein. An integrated analog sensor is sealingly contained within the opening. The field instrument further contains an external analog sensor. An analog to digital converter converts the analog signals to digital readings. An external digital sensor is also provided, with the digital output being communicated through a second opening within the enclosure. A control member that receives, stores and processes the digital readings is positioned within the enclosure. A communication module is included to transmit the digital readings to a remote computer. The communication module allows for two way communication between the field instrument and remote computer. The remote computer may be a server that allows for access by many users. The communication module also allows for locally accessing the digital readings via a serial port to a local terminal.

Abstract: A method, computer program product and apparatus for estimating the pneumatic pressure of a tire on a vehicle, comprising the steps of: receiving as an input a vehicle status sensor signal; estimating first parameter values of an adaptive filter based on a predetermined model on the vehicle status dependent on the vehicle status sensor signal; calculating, dependent on said first model parameter values, a first tire pressure indication value (?) being dependent on and indicative of the pneumatic pressure of the tire. Specifically, the vehicle status signal may be an input a wheel angular velocity signal (1) and a lateral movement indication signal; the adaptive filter is based on a predetermined model on lateral vehicle dynamics dependent on the angular velocity of said wheel and the lateral movement of said vehicle.

Abstract: A device for impact sensing is described which detects an impact by a pressure, a normalized signal being supplied to a processor for analyzing the pressure signal. This normalization may occur either in the pressure sensor, by the sensor element itself or by a signal preprocessor, or in the processor.

Abstract: A control system coupled to a pressure sensor calibrates the pressure sensor. The control system may measure a plurality of capacitance values at a plurality of corresponding applied voltages to compare the values with a first calibration mechanism generated by sample pressure sensors in a comparison. A final calibration mechanism may be generated by adjusting the first calibration mechanism in response to the comparison. The unknown differential pressure may be applied to a diaphragm of the pressure sensor. A capacitance value at the unknown differential pressure may then be measured. Using the final calibration mechanism, the differential pressure at the measured capacitance value may be retrieved.

Abstract: A tire pressure monitoring system as described herein leverages a real-time onboard vehicle mass estimate to determine whether tire pressure is appropriate for the current loading conditions. The system is suitable for use with vehicles having two or more placard tire pressures (with two or more corresponding tire loading capacities). The system can notify the driver to adjust the tire pressure to the proper placard tire pressure for the given load conditions, and/or initiate automatic inflation or deflation by an onboard tire inflation system.

Abstract: A pressure sensor 11 is provided with a connecter housing 30 having a pressure sensing element 20 arranged on an end surface thereof, a sensor housing 40 constructed to have the connecter housing 30 inserted thereinto, a pressure chamber 452 defined between the end surface of the connecter housing 30 and the sensor housing 40, and a compensation circuit 21 for performing the processing and operation of a measured signal of the pressure sensing element 20 to output the measured signal.

Abstract: A parameter of a fluid passing through a pipe is measured using a spatial array of sensors disposed at different axial locations along the pipe. The spatial array includes at least two overlapping sub-arrays. Using the pressure signals, a signal processor determines a spatial correlation matrix for each of the sub arrays. The spatial correlation matrices from the sub-arrays are averaged, and the averaged spatial correlation matrix is used as input to an adaptive array processing algorithm. The pipe may be open ended such that it can be positioned within the fluid flow for forming a portion of a sensing device.

Abstract: An apparatus for measuring a parameter of a fluid passing through a pipe includes a spatial array of at least two sensors disposed at different axial locations along the pipe. Each of the sensors provides a signal indicative of unsteady pressure within the pipe at a corresponding axial location of the pipe. A signal processor constructs at least a portion of a k-? plot using the signals and detects at least one ridge in the k-? plot. A slope of the at least one ridge is indicative of the parameter of the fluid. The signal processor determines a quality metric by comparing an accumulated energy (power) of k-? pairs along the at least one ridge with an accumulated energy (power) of k-? pairs along at least one ray extending in the k-? plot. The quality metric is indicative of a quality of the at least one ridge.

Abstract: A method of detecting nozzle clogging by the use of threshold values that can be set easily is accomplished. Also, an analytical instrument equipped with a nozzle clogging detector using threshold values that can be set easily is accomplished. Threshold values corresponding to aspiration volumes of sample are calculated from plural threshold values (P1, P2, and P3) that have been set for discrete aspiration volumes (SV1, SV2, and SV3), respectively. The threshold values are found for each of plural aspiration programs corresponding to plural sets of conditions under which a sample is diluted, and for each of plural aspiration programs corresponding to plural kinds of samples. Threshold values are found for each of plural detection sensitivities.

Abstract: A portable, handheld electronic navigation device includes an altimeter and a GPS unit. An internal memory stores cartographic data, for displaying the cartographic data on a display of the navigation device. Accordingly, the device is capable of displaying cartographic data surrounding a location of the unit as determined by GPS and altitude information as determined by the barometric altimeter and GPS. The device provides an enhancement of the calibration and hence the accuracy of barometric altimeter measurements with the aid of derived altitudes from a GPS. The device is able to determine the need for calibration and perform the subsequent computations necessary to facilitate the calibration. Furthermore, the device is able to determine a correction quantity that should be applied to barometric altitude readings, thereby allowing the device to be calibrated while in motion. Both of these features ultimately result in a more accurate determination of altitude.

Abstract: A detection method of reduced air pressure of tires based on the rotational speed of wheels mounted on a vehicle. The method includes steps of: determining the rotational speed of each wheel, memorizing the rotational speed of each wheel, determining the loading sensitivity of the dynamic load radius of tires caused by movement of a load during turning, comparing the loading sensitivity with the loading sensitivity of the dynamic load radii of tires at initialization which are preliminarily memorized, and judging decompression of tires based on the result of the comparison. Further, a loading sensitivity-calculating method of determining the loading sensitivity of the dynamic load radii of tires includes steps of: determining a lateral acceleration during turning of a vehicle, determining the shift rate of a judgment value which is the relative comparison of rotational speed of wheels on a pair of diagonals of a vehicle, and determining the loading sensitivity.

Abstract: A method and apparatus is disclosed, particularly, though by no means exclusively, useful in touch-screen computer CRT display systems and the like, and more generally in other force and/or torque measurement systems, as in weighing and the like, in which (1) lineal and/or rotational acceleration of the system is sensed in response to inertial interference effects such as tilt or movement that introduce errors into the force and/or torque measurements, and/or (2) inertial error correction from the force data itself is obtained, such as derivative order corrections; and such data is used to correct the force and/or torque measurements. A novel calibration technique for deriving appropriately descriptive coefficients to the particular system for the correcting data, is also disclosed.

Abstract: Vehicles equipped with air brake systems and onboard vehicle management computers may be programmed to determine normal operating variables for the air compressor system used for maintaining air brake system pressure. The algorithm used determines normal compressor cut-in and cut-out pressures and actual rise times from cut-in to cut-out by compensating for periods of exogenous air pressure demand.

Abstract: The present computer card for electro-pneumatic calibrators with system management corresponds the an equipment for calibrating vehicle tires, automatically, made up by electronic, electric and mechanical components commanded by computer programs, of simple handling, fast and extremely safe, which can be remotely monitored and switched on by the insertion of coins.

Abstract: A transducer is provided in communication with a power supply of a powered tool for detecting power consumption associated with powered and non-powered operational states and generating a power consumption signal. A measuring implementation is provided for receiving the power consumption signal and measuring intervals associated with at least one of the powered and non-powered operational states, so as to produce an operational history of the powered tool corresponding to a predetermined time period. A production counter is used for counting production units produced by the powered tool during the predetermined time period. A correlating implementation is provided for correlating the operational history with the production units, so to as generate a productivity indicator.

Abstract: A method and device for reducing signal drift on a balloon catheter mounted pressure sensor by adjusting for signal gain and/or zero offset, and by separately calibrating the constant signal component and the time-varying signal component of an uncalibrated source signal to produce a calibrated source signal.

Abstract: A system for real-time signal processing for vehicle monitoring, including a first device disposed in a tire of a vehicle and producing a signal that is a function of a tire contact time period, during which a point at the tire circumference stays in contact with the ground, and a second device operative to repetitively perform a first task of processing the signal to calculate the tire contact time period at a first predetermined rate, and to repetitively perform a second task of calculating a tire load based at least in part upon the calculated tire contact time period at a second predetermined rate, wherein said second predetermined rate is less than said first predetermined rate.

Abstract: A field instrument and system for obtaining pressure, flow and temperature data from a facility. The field instrument includes an enclosure having an opening therein. An integrated analog sensor is sealingly contained within the opening. The field instrument further contains an external analog sensor. An analog to digital converter converts the analog signals to digital readings. An external digital sensor is also provided, with the digital output being communicated through a second opening within the enclosure. A control member that receives, stores and processes the digital readings is positioned within the enclosure. A communication module is included to transmit the digital readings to a remote computer. The communication module allows for two way communication between the field instrument and remote computer. The remote computer may be a server that allows for access by many users. The communication module also allows for locally accessing the digital readings via a serial port to a local terminal.

Abstract: An air flow regulator includes a damper (14) and an air cylinder (20) operatively connected with the damper (14) to adjust a damper setting. A pressure sensor (52) indicates a pneumatic pressure in the air cylinder (20). An air pressure regulator (42) is operatively connected with the air cylinder (20) to pressurize and exhaust the air cylinder (20) responsive to an electrical input (70). The air pressure regulator (42) includes a calibration table (64) associating steady state air cylinder pressure values with regulator shut-off pressure values. Responsive to the electrical input (70) updating a steady-state air cylinder pressure value, the air pressure regulator (42) pressurizes or exhausts the air cylinder (20) until the pressure sensor (52) indicates a pressure corresponding to a regulator shut-off pressure value associated in the calibration table (64) with the updated steady-state air cylinder pressure value, whereupon the air pressure regulator (42) ceases the pressurizing or exhausting.

Abstract: A system has a memory in a vehicle for registering an identification of a tire air pressure sensor device in the memory. The tire air pressure sensor device is provided for a tire of the vehicle. The system further comprises a receiving unit configured to receive an unlikely signal which is transmitted from the tire air pressure sensor device. The unlikely signal is unlikely to be transmitted therefrom under normal circumstances. The system also comprises a first registering unit configured to register the identification of the tire air pressure sensor device in the memory in response to the receive of the unlikely signal.

Abstract: A method and an apparatus for determining fluid flow through a pressure regulator is disclosed. The pressure regulator is disposed in a fluid flow passage and has a throttling element moveable in the flow passage. A stem is attached to the throttling element. The apparatus includes a first pressure sensor for measuring pressure upstream of the throttling element, a second pressure sensor for measuring pressure downstream of the throttling element, and a travel sensor for detecting the position of the throttling element. A processor is provided which includes a stored algorithm for determining flow rate based on the measured pressure and travel values and for calibrating the pressure regulator using a temporary flow meter disposed downstream of the throttling element. A system and method is also provided for calibrating a temperature transmitter associated with the pressure regulator.

Abstract: A method for providing a corrective modulation signal to suppress an acoustic pressure wave in an operational system.

Abstract: A simple method of handling thermomechanical coupling for temperature computation in a rolling tire. First, the sensitivity of the tire elastic response to changes in material stiffness is characterized using the “deformation index”. Then, using a commercial finite element program and an appropriate user subroutine, heat generation is expressed as a function of the local temperature using a simple algebraic expression involving the temperature dependent material properties and the deformation indices. Temperatures are computed using the finite element program with the coupling information contained in the user subroutine. The result is a non-iterative method for a fully-coupled thermomechanical analysis of a tire. The effects of compound changes on tire temperature distribution can also be estimated using the deformation index. The method applies to the energy loss and temperature calculations under both steady-state and transient conditions.

Abstract: This dynamic calibration qualifier relates to a tool monitor and assembly qualifier that verifies that the correct number of fasteners have been properly installed into an assembly. The device monitors an analog signature created by the tool and has the ability to dynamically calibrate itself while the tool is running. In the preferred embodiment, the stored variable is a clutch offset identified during a calibration phase. In a pulse tool, the programmed microprocessor is configured to identify and store the peak pressure of the first three pulses which are averaged together. The clutch offset is added to the average pulse value from which the clutch threshold is generated.

Abstract: The present invention provides an objective bubble point pressure determination method enables new applications of downhole PV (Pressure Volume) test results such as in situ measurement of the bubble point pressure for use as a quality control parameter for sampling. The present invention provides a method and apparatus to fit data points to a curve and to smooth these points over an interval of N points. The derivative of the curve is determined to obtain peak acceleration. The peak acceleration represents the bubble point pressure. This bubble point pressure is verified by comparison to changes in fluid compressibility and visual observation of a pressure volume plot history.

Abstract: A method of calibrating pressure sensitive paint is provided comprising the steps of: illuminating the paint under a range of pressures and temperatures; measuring the intensity of light emitted by the paint following each illumination thereby measuring decay curves; and performing a curve fit of the decay curves to determine characteristic constants. These constants can then be used to generate a model of decay curves and a polynomial relating pressures and temperatures for ratios of intensities over gated areas of the model decay curves can be calculated. Pressure determination at the calibrated paint can then be performed by illuminating the paint, measuring the intensity of light emitted by the paint over two of the gated areas, determining the ratio of the gated area intensities and finally determining the pressure and/or temperature from the polynomial using the determined ratio of the gated area intensities.

Abstract: A system and computer implemented method for enabling field service of machines and training of field service personnel. The method comprises the steps of generating at least one validated sequence of instructions for at least one maintenance task and delivering the at least one validated sequence for use in performing the at least one maintenance task.

Abstract: A method and control system that monitors the high frequency or commonly referred to as the “noise” component of a measurement signal to detect plugging conditions in fluid flow systems monitored by DP-cell based sensors. This high frequency component has contributions from the process factors like disturbances, user actions and random effects like turbulence. A test statistic &thgr;(t) has been developed that monitors the proportion of variance introduced by the first two factors and the third factor. By monitoring this proportion, it is possible to detect a frozen sensor that is characterized by a dramatic reduction in the variance due to process factors over a sufficiently long detection window. The method and control system uses random sampling intervals to improve data quality. The sampling rate is also reduced by taking samples at a lower rate and then reconstructing the original signal from fewer data points.

Abstract: A sign of abnormality of a valve apparatus during its operation is grasped, an abnormal position and a portion requiring repair are specified, a range of inspection of an electric valve is limited and the degree of the sign of abnormality is judged without touching at all the valve apparatus. A driving force sensor provided to a driving portion of a valve apparatus is connected to a diagnosing apparatus, an energy sensor for detecting feed energy to the driving portion and a vibration sensor for detecting vibration of the valve apparatus are provisionally fitted to the valve apparatus. A data conversion unit converts the detection signals outputted from these three kinds of sensors to predetermined signals.

Abstract: There is provided a failure diagnostic system for an atmospheric pressure detecting device, which is capable of rationally determining whether that device has failed or not and is capable of improving the diagnostic accuracy. The failure diagnostic system is comprised of an atmospheric pressure sensor for detecting an atmospheric pressure of the air taken into an engine; a condition determination section for determining that conditions required for determining that the atmospheric pressure sensor has failed are satisfied if the number of operations, in each of which the engine continuously operates for a predetermined period of time, has exceeded a predetermined number; and a failure diagnosis section for determining that the atmospheric pressure sensor has failed if a variation in the atmospheric pressure over a period of time equivalent to that predetermined number is equal to or less than a predetermined value and the required conditions have been satisfied.

Abstract: A system for determining a leak rate of a device during an adiabatic cooling phase is provided. The system includes a leak rate training system receiving leak rate calibration data, such as pressure data or mass flow data for a device having a known leakage rate. The leak rate training system generates an adiabatic cooling model from the leak rate calibration data, such as by solving a finite difference equation for one or more unknown process variables that are dependent on the adiabatic cooling parameters of the device. The system further includes a leak rate detection system receiving the adiabatic cooling model and leak rate data and determining a leak rate component of the leak rate data using the adiabatic cooling model, such as by using the variable values determined through solving the finite difference model to interpolate between the leak rate calibration data that was gathered using known leakage rates.

Abstract: A pressure transmitter with an output predicting the magnitude of error in the pressure transmitter's output. A pressure sensor is adapted to sense a process pressure. A controller coupled to the pressure sensor generates a transmitter output representing the process pressure. A memory stores predetermined data predicting magnitudes of transmitter output error as a function of cumulative excessive sensor output levels, and also stores a record of cumulative excessive sensor output levels. The controller calculates a predicted present magnitude of transmitter output error as a function of the accumulated record and the predetermined data, and generates the prediction output.

Abstract: A method of calibrating a pump that is subject to variations in flow rate based on inlet pressure variations, such as a peristaltic pump found in medical instruments. The pressure at the inlet of the pump is measured and recorded during prior uses of the pump. A mean or average inlet pressure is derived from the measurements, either directly or indirectly from the measurements of using regression techniques, as a way of forecasting the inlet pressure during the next use of the pump. The pump is then calibrated at an inlet pressure that is set or adjusted to match the mean or average inlet pressure. The calibration is thus accurately performed for the pump, and is independent of the absolute accuracy of the inlet pressure sensor.

Abstract: A portable altimeter of the present invention is provided with a movement determining unit for determining whether or not the altimeter is at a standstill or moving by comparing an amount of change in altitude with a prescribed standstill threshold value and movement threshold value. When the standstill mode is set, the moving mode is then set only when the amount of change equals or exceeds the movement threshold value, and when the moving mode is set, the standstill mode is then set only when the amount of change falls below the standstill threshold value.

Abstract: The invention relates to an altimeter for detecting and displaying the altitude above the sea level of a location by measuring the ambient atmospheric pressure. In order to compensate for changes in air pressure due to meteorological reasons, such as temperature, an adjustment or reset mechanism is provided with the purpose of adjusting or resetting the altimeter to a given stored height at a given moment. This is only effected if at that moment, the air pressure that has been measured indicates height coinciding with the given stored height within a predetermined tolerance limit.

Abstract: A pressure sensor is provided which is tolerant to noise such as electromagnetic waves, is configured so as to be capable of easily selecting a system environment in which a sensor signal, commonly used for various kinds of systems, can be freely read in at timing as required by a system, and is able to realize reduction in size and cost suitable for automotive use. An element portion for detecting pressure and a circuit portion having a signal processing function are integrally accommodated in the same package. An interface section 24 optimized to interface with external wiring, an A/D conversion section 25 for digitally encoding an analog processed detection signal of the sensor, and a digital processing section 26 for converting the digitized signal into a desired serial signal are added to the circuit portion 2.

Abstract: A method and an apparatus for determining fluid flow through a pressure regulator is disclosed. The pressure regulator is disposed in a fluid flow passage and has a throttling element moveable in the flow passage. A stem is attached to the throttling element. The apparatus includes a first pressure sensor for measuring pressure upstream of the throttling element, a second pressure sensor for measuring pressure downstream of the throttling element, and a travel sensor for detecting the position of the throttling element. A processor is provided which includes a stored algorithm for determining flow rate based on the measured pressure and travel values and for calibrating the pressure regulator using a temporary flow meter disposed downstream of the throttling element. A system and method is also provided for calibrating a temperature transmitter associated with the pressure regulator.

Abstract: A pressure signal from a differential pressure transducer is dynamically compensated for error, such as zero point drift, due to time passage or temperature change. A processor associated with a pressure transducer employs an algorithm to continuously monitor the pressure signal to determine when signal characteristics indicate zero signal level. Then the algorithm determines a current correction factor or updates a previously determined correction factor, and records the current correction factor in a non-volatile memory as a function of ambient temperature. When the signal characteristics indicate other than a zero signal level, such as when differential pressure is non-zero, the algorithm recalls from memory and applies the most recently determined correction factor for a corresponding ambient temperature. Suitable time intervals for determining a current correction factor are found by monitoring the process signal and seeking those time periods when the signal is both calm and quiet, i.e.

Abstract: A sensed-pressure-data converter having a circuit for reducing a fluctuation of the output due to a fluctuation of a resistance and a resistance changing characteristic of a pressure sensitive resistance element and for reducing the output offset and offset drift of the pressure sensitive resistance element. The converter of the invention comprises a pressure sensitive resistance element (1), and a controller (2). The controller is an electric circuit connected to the pressure sensitive resistance element for detecting the electric characteristic of the element and includes A/D converters (3, 4), a D/A converter (6), and a memory (5). The controller compensates the electric characteristic due to a resistance change of the pressure sensitive resistance element and issues it from the D/A converter (6).

Abstract: A sensing element detects a predetermined physical quantity and generates a sensor signal. A signal processing circuit processes the sensor signal and generates an output signal. A first memory circuit stores characteristics control data used for adjusting sensor output characteristics. An adjusting circuit performs an adjustment to equalize the sensor output to a target value based on the characteristics control data stored in the first memory circuit. A second memory circuit stores fine control data used in a fine adjustment performed to correct a deviation resulting after the adjustment based on the characteristics control data stored in said first memory circuit.

Abstract: A method for measuring the weight of a vehicle and/or of its load comprising measuring the temperature and pressure of at least a significant number of tires of said vehicle, a temperature standardized pressure based on a selected standardization temperature, summing the standardized pressures and determining weight of the vehicle and/or its load based on the sum of the temperature compensated pressures and a conversion factor.

Abstract: An apparatus for use in an aircraft for determining and displaying a reading which is indicative of pressure density at any instant in time, comprises sensing means for determining both ambient air pressure and ambient air temperature at any instant in time, and outputting an electrical signal having a value which varies in accordance therewith. Calculating means are provided for combining those electrical signals and outputting a weighted signal for pressure density having a value based on an index value of zero for a pressure density at sea level when the ambient temperature is 59° F. and the ambient pressure is 29.92 inches of mercury. A microprocessor computer means has random access memory and read only memory, and an output signal driver for outputting a signal indicative of pressure density at any instant in time to a display.

Abstract: A method is provided for determining the barometric pressure external to an air intake of an internal combustion engine, comprising the steps of: (a) providing a pressure value indicative of an absolute pressure in the intake manifold of the engine; (b) providing a mass airflow value of the airflow into the engine; (c) characterizing a pressure drop across the intake system based on the mass airflow value; and (d) determining a barometric pressure based on the pressure value and the pressure drop, such that the pressure drop is indicative of the pressure differential between the atmospheric pressure and the pressure in the intake manifold. Furthermore, the determination of the barometric pressure may be triggered when the throttle blade reaches a predetermined throttle threshold position which is a function of the rotational speed of the engine.

Abstract: An apparatus for alarming decrease in tire air-pressure which alarms decrease of internal pressure of a tire on the basis of a rotational information obtained by tires attached to a four-wheeled vehicle. The apparatus comprises rotational information detecting means; memory means for storing the rotational information; calculation processing means for calculating a reciprocal number of a turning radius and calculating a judged value; first judging means for comparing the judged value with a reference value at every regions of the turning radius; and second judging means for canceling a judgement of decrease of internal pressure when a difference between the judged values in the right and left turning regions is different from a difference between reference judged values in the right and left turning regions which are obtained at a time of initializing run.