Abstract: An apparatus for measuring the flow rate of a gaseous or liquid medium includes a baffle member which is poised in the stream on an elastic holder and permitted to execute inherent periodic motions. The flowing medium exerts a damping action on the moving element and the energy lost to the medium is related to the flow rate. The inherent velocity of the baffle is sensed by an inductive velocity sensor and the resulting signal is used to alter the current through a coil which produces an accelerating magnetic field that acts on conductors rigidly attached to the baffle. Thus, the energy required to maintain the inherent motions of the baffle is known and the flow rate may be inferred.

Abstract: An ultrasonic nondestructive testing system and a "sled" for use in such a system are provided for nondestructively inspecting a workpiece. The "sled" includes an ultrasonic search unit effective to radiate or transmit ultrasonic energy in response to a driving signal and to receive ultrasonic energy and produce a received signal corresponding to the incident ultrasonic energy. The sled includes a sealed chamber filled with a liquid couplant. A resilient, elastomeric diaphragm forms one side of the chamber and is adapted to slide along the surface of the workpiece. An ultrasonic search unit projects into the chamber so as to be acoustically coupled to the diaphragm. In addition, an elastomeric member having a high acoustical attenuation and an acoustical impedance corresponding to that of the liquid couplant is provided inside of the chamber for absorbing spurious ultrasonic energy.

Abstract: An apparatus for inducing vibratory oscillations in an airfoil is provided to simulate the dynamic aeroelastic interaction between the airfoil and a gas flow field. The apparatus includes first means for supporting the airfoil during inducement of the vibrations and second means movable in response to variations in magnetic flux to rotate the airfoil about first and second axes. Third means are provided for generating a variable magnetic flux field in response to an electrical control signal provided by fourth means.

Abstract: Device for nondestructive ultrasonic testing of cylindrical parts, comprising a basin in which the part to be tested, for example a journal bearing provided with an antifriction alloy is immersed. The basin is mounted on a revolving plate having a gear driven by means of an inclined-tooth pinion. A vertically movable horizontal arm, depending upon diameter of the part to be tested, carries two piezoelectric transducers and an arcograph, the marking of the bonding fault area on the surface of the part to be tested being effected by means of an electric arc produced between one trace element of the arcograph, which receives a voltage signal from the monitor of a fault detector through the control assembly of the arcograph, and the inner surface of the part to be tested. The entire cylindrical surface is explored along a tangent of partially superposed helixes and the pitch of the helix is equal to, or smaller than the diameter of the piezoelectric transducer crystal.

Abstract: The present device has a three-piece spring-loaded main housing with a cavity therein, and an accelerometer assembly disposed in said cavity and arranged therein to be held between a plurality of O-rings located on both ends thereof. One of said pieces of said main housing comprises a plastic tip. The entire main housing is located within a sleeve and is spring-loaded to force said plastic tip against the rotating shaft whose displacements are being monitored.

Abstract: A three-chamber gas meter having a two-chamber cartridge inserted into a casing, the interior of which forms the third chamber. The meter is of compact design and readily mass produced. The cartridge carries a valve plate which communicates to each of the chambers and also to the inlet and the outlet. A rotary valve connected to the valve plate will sequentially and selectively connect the chambers between the inlet and the outlet to measure the gas flow through the meter. A flag and crank assembly is operatively associated with the cartridge to connect the rotary valve and the diaphragms, which expand and contract to actuate the internally connected flag and crank assembly, thus to rotate the rotary valve. A pair of flag rods are journaled in the cartridge and included in the flag and crank assembly.

Abstract: This is an ultrasonic transducer scanning support system comprising at least three arms serially joined in pivotal relation one to the other and to a base. Three position transponders are mounted on the base with each of the pivoted arms operatively coupled to a transponder whereby signals are developed representative of the position of a transducer mounted on the end of the third arm which control the origin of an indicating means to correspond to the position of the transducer.

Abstract: In a device for measuring ultrasonically the flow of gas, for example the air flow in the induction duct of an internal combustion engine, an upstream piezo-electric transducer is located in a plenum chamber upstream of a measurement duct and a downstream piezoelectric transducer is located in a seating in the measurement duct. To reduce vorticity in the gas flow the upstream transducer is seated at the apex of a frusto-conical element in the inlet chamber and the seating of the downstream transducer is tapered externally.

Abstract: A method of and apparatus for imaging objects utilizing acoustic waves wherein an acoustic beam or beams are generated at one or more frequencies and are focused into proximity with the object to generate output acoustic energy at a different frequency or frequencies resultant from nonlinear interactions with the resultant production, after detection and conversion to electric output signals, of high resolution, enhanced images.

Abstract: An acoustic microscope system in which the insonification frequency f.sub.s is continuously modulated, at a rate asynchronous relative to the optical scanning frequencies, to minimize acoustic speckle; the filter means employed to develop a video signal from the scanning beam has its center frequency continuously varied to track the insonification frequency changes. The filter means employs a constant-frequency IF stage, utilizing an IF mixer that subtracts f.sub.s from the initial scanning information but adds a fixed carrier to allow for subsequent effective filtering. A combined deflector and demodulating light shield structure provides for improved alignment of the system optics. For optically opaque specimens, a polished surface of the specimen is used as the acoustic-optic interface, with no coverslip required and both optical and acoustical images derived from a single scanning beam. Shear-mode insonification is employed for improved resolution and to examine special properties of some materials.

Abstract: An ultrasonic weld inspection system has an ultrasonic transmitting transducer and an ultrasonic receiving transducer on the same side of the weld. A beam of ultrasonic energy from the transmitting transducer directed into the weld center impinges upon a flaw and the receiving transducer is aligned to receive only a portion of the ultrasonic energy beam scattered by the flaw while avoiding receiving reflections of the beam off the flaw and off weld contour irregularities.

Abstract: A multi-degree-of-freedom shock and vibration testing system which includes a specimen-holding table having short projections engaged by hydraulic actuator assemblies. Each actuator assembly includes a pair of hydraulic actuators on opposite sides of the projection and a servo valve for connecting the actuators to a source of pressured hydraulic fluid and to a drain, to maintain the pair of actuators pressed firmly against opposite sides of the projection while moving substantially synchronously. A hydrostatic bearing pad bears against a rounded end of each actuator and against opposite sides of the projection, to permit the projection to slide perpendicular to the motion of the actuators and to pivot.

Abstract: Apparatus for the ultrasonic examination of an object comprising a transmer for transmitting pulses of ultrasonic energy into the object and a receiver for receiving echoes of the pulses of ultrasonic energy reflected by acoustic impedance discontinuities within the object, wherein the transmitter comprises a central transducer adapted to transmit pulses along a single axis and a plurality of annular transducers positioned concentrically with the axis of the central transducer. The receiver comprises the central transducer, the central transducer being adapted to receive echoes of pulses transmitted into the object by each of the central transducer and the annular transducers which are reflected along the single axis thereof, the apparatus further comprising circuitry for analyzing the received echoes of pulses transmitted by each of the central transducer and annular transducers to extract velocity, scattering, and multiple reflection information.

Abstract: A microscope for scanning an object with light and acoustic waves and producing both acoustic and optical images thereof. The microscope includes optical and acoustic lenses that focus both the light and acoustic waves on substantially the same point on the object. In one portion of the microscope the acoustic waves and light propagate coextensively through the same medium. The apparatus generates a simultaneous presentation of both acoustic and optical images formed by the microscope.

Abstract: A device for bypassing flow rate pulsations resulting in reverse flow and abrupt flow rate surges around a volumetric flow rate transducer includes a housing defining a chamber. One end of the chamber is coupled in fluid communication with the inlet or upstream side of the transducer while the other end of the chamber is coupled in fluid communication with the outlet or downstream side of the transducer. A flexible, fluid impervious diaphragm is mounted in the housing so as to divide the chamber into two compartments. The diaphragm is affixed to the walls of the chamber so as to maintain a fluid seal between the two compartments of the chamber. When a forward flow rate pulsation occurs the resultant rise in the fluid pressure differential between the upstream and downstream compartments of the chamber will shift the diaphragm toward the downstream compartment. As the diaphragm moves, fluid is forced out of the downstream compartment and into the fluid stream on the downstream side of the transducer.

Abstract: A sonic interference suppressor has a wiper of flexible material for wiping loose foreign material and excess water from a weld during ultrasonic inspection of the weld. A thin film of water between the contour conforming wiper and the weld passes unwanted ultrasonic energy into the wiper and on into foamed backing material.

Abstract: The invention is directed to an improvement for a fluid-volume apparatus for measuring a fluid under pressure. A measuring chamber housing with a movable measuring part is arranged in a pressure-resistant outer housing. A fluid medium is present in the space between the outer housing and the measuring-chamber housing. The improvement includes separating this space between the measuring-chamber housing and the outer housing from the fluid to be measured in a fluid-tight manner and providing a pressure-responsive element for placing the above-mentioned space between housings in pressure-equalizing communication with the liquid to be measured whereby the pressure of the fluid medium in the space between the housings is at a pressure which corresponds to the pressure of the liquid to be measured.

Abstract: The object of the invention is an ultrasonic echo-tomographic device. An alignment of transducers coupled to the body under observation emits flat ultrasonic radiation. The wave fronts of the echoes received in response at each line parallel to the front of the transducers are transformed by means of an electrical chain, without alteration of phase, in a crystalline medium. A laser and an optical system form by Bragg diffraction the images of these lines which are picked up by a vibrating mirror and projected onto the target of a television camera. The invention is applicable in echo-tomography and enables 1000 images per second to be obtained.

Abstract: A flow meter includes a variable area obstruction mounted in a conduit and a differential pressure transducer having its two ports mounted on opposite sides of the obstruction in fluid communication with the fluid flowing through the conduit. The variable area obstruction is formed of one or more flexible leaves which extend into the flow stream and are deflectable under the influence of fluid pressure, such that an increased flow rate increases the deflection of the leaves and decreases the area of the obstruction.

Abstract: An automatic distance amplitude correction device for automatically correcting for amplitude variations and signals caused by the attenuation of sound propagating through a test specimen wherein a signal is transmitted through a test specimen and the reflection is detected and furthermore, a through signal is detected after the signal has passed through the test specimen only a single time and utilized to provide improved automatic distance amplitude compensation.