Abstract: A differential pressure sensor apparatus for use in a fuel delivery system measures the differential pressure of the fuel between a point immediately upstream and a point immediately downstream of a fuel monitor element. The differential pressure sensor apparatus uses an electronic transducer to monitor differential pressure and may be used with interlocks to shutdown fuel delivery if the measured value of the differential pressure is above a predetermined threshold value and to notify an operator of the fuel delivery system of such an increase in the differential pressure.

Abstract: A liquid flow metering system is disclosed which includes a pump disposed between a liquid supply and a reservoir. The reservoir includes an inlet connected to the pump, an air/liquid outlet and a liquid outlet. The air/liquid outlet is connected to an air separation chamber. The liquid outlet is connected to a flow meter and a liquid outlet valve. The air separation chamber is connected to an air outlet. The air outlet is connected to an air release valve. The air separation chamber accommodates an optical sensor for sensing the presence of air in front thereof and within the air separation chamber. The optical sensor, air release valve and liquid outlet valve are all linked to a controller. When the optical sensor senses air in front of the optical sensor, the sensor sends a signal to the controller to open the air release valve and close the liquid outlet valve.

Abstract: A scaled quadrature pulse output signal is generated for representing direction and volume in predetermined increments of the flow of a liquid or a gas through a meter. An unscaled pulse signal is received from a meter. A scaling factor is applied to each unscaled pulse signal for accurately representing an increment of volume. The increments are sequentially added or subtracted to/from one another (depending upon flow direction) and a scaled quadrature output signal is provided for indicating the direction of flow and the volume of flow in predetermined increments.

Abstract: A scaled quadrature pulse output signal is generated for representing direction and volume in predetermined increments of the flow of a liquid or a gas through a meter. An unscaled pulse signal is received from a meter. A scaling factor is applied to each unscaled pulse signal for accurately representing an increment of volume. The increments are sequentially added or subtracted to/from one another (depending upon flow direction) and a scaled quadrature output signal is provided for indicating the direction of flow and the volume of flow in predetermined increments.

Abstract: An optimized Coriolis mass flow meter is disclosed which has improved stability to excitations caused by external influences. A primary source of improvement involves determining by modal analysis of the flow conduit a location for the sensor means that minimizes the influence of external excitation of one or more of the first in phase bending mode, the first out of phase bending mode, the first out of phase twist mode, the second out of phase twist mode, the second out of phase bending mode and the third out of phase bending mode.

Abstract: Apparatus and accompanying methods for implementing both an accurate densimeter and a net oil computer utilizing a common Coriolis meter assembly is described. This apparatus measures density of an unknown fluid by first determining the period at which both flow tubes contained within a dual tube Coriolis meter oscillate while the unknown fluid passes therethrough. The apparatus then squares the result. Thereafter, the density of the unknown fluid is determined as a linear function that relates the squared tube period measurement for the unknown fluid, and squared tube period measurements and known density values for two known fluids, such as air and water, that have previously and successively passed through the meter during calibration.

Abstract: Apparatus and accompanying methods for implementing both an accurate densimeter and a net oil computer utilizing a common Coriolis meter assembly is described. In essence, this apparatus measures density of an unknown fluid by first determining the period at which both flow tubes contained within a dual tube Coriolis meter oscillate while the unknown fluid passes therethrough. This apparatus then squares the result. Thereafter, the density of the unknown fluid is determined as a linear function that relates the squared tube period measurement for the unknown fluid, and squared tube period measurements and known density values for two known fluids, such as air and water, that have previously and successively passed through the meter during calibration. When used as a net oil computer, the inventive system obtains mass flow and temperature measurements from the same flow tubes.

Abstract: A method and electronic circuit for measuring the density of substances flowing through an oscillating container densimeter that measures the temperature of the oscillating container to determine the temperature coefficient of the spring constant about the axis of oscillation.

Abstract: A circuit for measuring the reactance of an AC reactance sensor which varies responsive to a condition to be sensed, such as pressure, is disclosed. The circuit comprises an oscillator coupled to the sensor for providing a time varying oscillator signal having a variable frequency and a substantially constant peak to peak voltage to the sensor, and a plurality of rectifiers coupled to the oscillator and to the sensor for providing the oscillator signal as a charging signal to the sensor and for providing discharging signals from the sensor, the discharging signals being a function of the reactance of the sensor, and an amplifier coupled to the rectifiers and to the oscillator for providing an input control signal to the oscillator to control the frequency of the oscillator signal as a function of the reactance of the sensor.

Abstract: A circuit is coupled to an external power supply and is coupled to a non-live zero, two wire DC current transmitter (e.g. 4-20 MA output) for converting such current to a live-zero DC output current signal (e.g. 0-20 MA output) and for powering such transmitter. The circuit has a first current to voltage converter for converting the transmitter current signal to a voltage signal, and a second current to voltage converter coupled to receive the circuit output current signal and an offset current from an offset current source for converting the sum of the circuit output and offset currents to a second voltage signal. A comparator is used for comparing the first and second voltage signals to provide the live-zero output current signal representative of the non-live zero transmitter signal. The circuitry can also provide isolated power to the transmitter and feedback (closed loop) control of such power.

Abstract: An optimized Coriolis mass flow meter is disclosed which has improved stability to excitations caused by external influences. A primary source of improvement involves determining by modal analysis of the flow conduit a location for the sensor means that minimizes the influence of external excitation of one or more of the first in phase bending mode, the first out of phase bending mode, the first out of phase twist mode, the second out of phase twist mode, the second out of phase bending mode and the third out of phase bending mode.