Abstract: An electrical flowmeter having signal electrodes laterally spaced along a line perpendicular to fluid flow and sensitive to a voltage field set up in the fluid by a magnetic field is provided with helically coiled conductive windings disposed in a laminar arrangement in a plane parallel to the direction of fluid flow and wound in a helical spiral and connected to receive alternating current. The signal electrodes are spaced proximate to the outer coil windings, and a neutral electrode is provided at the helical vertex of the windings. The electrical field set up in the fluid impresses a voltage field across the signal electrodes proportional to relative fluid velocity and immune from quandrature and hydrodynamic effects.

Abstract: A continuous wave ultrasonic wave transmitter transmits modulated waves in two opposite directions being intercepted by a forward receiver and an aft receiver. The received signals are demodulated and the relative phase is used to obtain a speed reading. The wave length of the modulator signal must be larger than the two, preferably equal transmitter-to-receiver spacings. A similar but orthogonally arranged receiver system permits acquisition of a speed vector. Different modulation frequencies are to be used for different speed ranges; all these frequencies are transmitted simultaneously and selection of the desired one is made in the processing circuit only.

Abstract: The invention relates generally to measuring the air speed of an object moving within the earth's atmosphere. In particular, the invention provides apparatus which comprises means for causing an air flow to enter an electric E field chamber, proportional to air speed, a portion of the air in the air flow being ionized prior to entry into the E field. Air speed is measured by the current resulting from charge separation in the field.

Abstract: The ultrasonic air data system determines the relative velocity of an aircraft with respect to the medium in one, two or three directions. In addition, it may determine the speed of sound and the approximate temperature. In the one direction system, a first ultrasonic transducer transmits a pulse to a second transducer where it is detected and reflected back to the first transducer and again reflected to the second transducer. The pulse transmit times for each direction are determined, and the relative velocity, the speed of sound and the approximate temperature are provided as a function of the transit time. In the two or three direction systems, three or four transducers are positioned in a two or three dimensional configuration. In the first half cycle, the first transducer transmits a pulse to the second where it is reflected to the third or last transducer in a two-dimension system and then to the last transducer in a three-dimension system.

Abstract: An electromagnetic flow meter construction for substantially flush mounting within a surface past which a fluid is to flow. A pair of spaced electrodes in contact with the fluid are mounted along a line perpendicular to the fluid flow and an elongated electromagnet provides magnetic lines of force substantially perpendicular to both the fluid flow and the line of the electrodes to generate an electrical potential between the electrodes proportional to the fluid velocity.The electrode leads are oriented with respect to the electromagnet to minimize the quadrature voltage and the electromagnet is bifilar wound and utilized in a push-pull alternating current driving circuit. The electrode signals are applied to a synchronous detector to generate a direct current voltage proportional to the fluid velocity.

Abstract: An ultrasonic air movement vector and magnitude sensing apparatus using a three element ultrasonic probe and temperature sensor in combination with an electronic computational circuit to produce air movement signals indicative of magnitude and direction in at least three cardinal axes.

Abstract: This invention relates to an improvement in a flow sonde, particularly for measuring aerodynamic values in aircraft such as the total pressure, the static pressure and the total temperature. The improvement comprises thermally controlled resistor means in the sonde body, said means having a low increase of resistance within a specific temperature range and a high increase of resistance in an adjacent range, whereby there is obtained a high heating power at a low ambient temperature and a limitation of the power absorption when a predetermined temperature is reached.

Abstract: A pair of concentric electrodes are mounted at one end of a housing fixedly supported on a body and positioned in a fluid, the flow of which is to be measured relative to the body. A permanent magnet is rotatably mounted in the housing proximate to the electrodes and is rotatably driven. Reference signal generating means is also mounted in the housing to generate a pair of pulsating reference signals having a predetermined phase relationship with each other and with the rotation of the magnet. Alternating current signals are generated between the electrodes, these signals having a magnitude and phase in accordance with the speed and direction of fluid flow relative to the electrodes.

Abstract: A body means of electrically non-conductive material supports at least one pair of electrically conductive detecting electrodes disposed at opposite portions of the body means. Means is supported within the body means between the electrodes for producing an alternating magnetic field. An electrical circuit is connected to the detecting electrodes and includes indicating means. In one form of the invention, electrically conductive guard means is disposed adjacent the electrodes and means is provided for establising a potential on the guard means which is directly proportional to the potential on the detecting electrodes.