Matches 401 - 450 out of 506 < 1 2 3 4 5 6 7 8 9 10 11 >
Match Document Document Title
4414508 Method and apparatus for automated inspection of fastener holes by eddy current  
An automated eddy current fastener hole inspection apparatus and method for providing an automatic indication of the presence of a crack in structural members. The device automatically advances the...
4394831 Helmet metal mass compensation for helmet-mounted sighting system  
An electromagnetic system for determining the orientation including position of a helmet worn by a pilot is disclosed having a transmitting antenna for transmitting electromagnetic field vectors, a...
4393598 Borehole tool  
A surface activated multishot survey tool utilizes a dampened magnetic compass movably positioned within a probe to determine the direction of a borehole. Lamps in the probe are operable to light...
4387338 Method and apparatus for testing a metallic workpiece by inducing eddy currents therein  
A method for testing a metallic workpiece by eddy currents induced by a test coil in the workpiece, in which a measured variable that is a function of the test coil impedance serves as a measure...
4386318 Method and apparatus to compensate a gradiometer having first and second unwanted terms  
A device and method producing a compensated gradiometer signal from an uncompensated gradiometer signal having at least one unwanted term which varies as a function of magnetic field. The device is...
4383218 Eddy current flow detection including compensation for system variables such as lift-off  
Disclosed is an eddy current inspection system for nondestructive detection of subsurface flaws in regions of multilayer conductive structure that surround a fastener which joins the conductive...
4380735 Compensating feedback system for multi-sensor magnetometers  
A magnetometer having two or more sensor feedback systems provides improved accuracy by compensating for the effect of the feedback field in each system on the other systems. Each system has a...
4380734 Measuring magnetic intensity independent of speed in a succession of moving magnetic strips  
The magnetic intensity in a succession of strips (12) in an article (10) is measured by producing relative motion between the article (10) and a magnetic sensing head (23) to produce a succession...
4371837 Temperature compensated input power and output offset circuits for a hall effect transducer  
A temperature compensating circuit for taking into account operating temperature changes of a Hall effect transducer to compensate for Hall output DC offset changes using a resistance circuit...
4368429 Method and apparatus for suppressing noise during nondestructive eddy current testing  
A filter apparatus (2) is disclosed for filtering out any reoccurring noise (5) present in a defect signal (1) received from a flaw detection device (4) such as an eddy current test probe. Filter...
4364013 Magnetic transducer comprising a strained magnetic wire in a sheath of non-magnetic material  
A magnetic transducer is disclosed which utilizes the magnetostrictive effect for creating an easy axis of magnetization in the longitudinal axis of a magnetic wire having a high cobalt content by...
4355280 Accumulator condition indicator with spring biasing to indicate linear displacement of a piston  
An accumulator fluid indicator useful to measure the linear displacement of a piston without the use of a dynamic seal. A Hall Effect sensor mounted on the outer surface of the accumulator is used...
4351031 Nondestructive testing system having automatic set-up means  
An eddy current type of nondestructive testing instrument is disclosed in which the operating frequency is automatically adjusted in accordance with a comparison of output signals obtained in...
4331920 Magnetic or magneto-inductive materials tester with improved processing circuit  
A magneto-inductive materials tester has probes which, when brought into contact with the material, produce an electrical signal corresponding to properties of the material desired to be tested....
4330748 Frequency correction circuitry for pipeline sensor apparatus  
In one method of non-destructive inspection of bodies of ferromagnetic material such as buried or submerged pipelines, probes containing magnetic sensors scan the surface of the body to detect...
4327498 Magnetic compass compensation system  
In a magnetic compass compensation system suitable for use within a ferrous land vehicle, a secondary magnetic sensor senses, the total magnetic field as components along a three axis system drawn...
4326166 Correcting circuit for differential pick-up, comprising digital means  
A circuit for automatically correcting a signal given by a differential pick-up. Said circuit comprises as many corrective channels as there are frequencies in the signal. Each of said channels,...
4322683 Control apparatus for eddy current non-destructive testing using a digital compensating circuit  
Digital apparatus for controlling members by eddy currents comprising a sensor constituted by a primary winding and a secondary winding, an exciting sinusoidal voltage generator, a correcting...
4305283 Position determining apparatus  
A position determining apparatus comprising a taut electrically-conductive member; a pulse generator to feed a pulse of electric current along the member; a magnet located at a variable first point...
4303885 Digitally controlled multifrequency eddy current test apparatus and method  
Digitally controlled eddy current test apparatus for detecting flaws, their extent and location. The apparatus provides absolute and differential measurements. The apparatus employs...
4292588 Electromagnetic inspection tool for ferromagnetic casings  
An electromagnetic thickness tool is disclosed to produce a measurement of the wall-thickness of a ferromagnetic casing corrected for the effects of casing permeability. First apparatus provides an...
4291270 Apparatus with a permanent magnet for gauging the thickness of coatings on metal products with magnetic shunt to adjust for demagnetization of the permanent magnet  
An apparatus for gauging the thickness of coatings on metal products comprises a casing which accommodates a wheel system; a spring actuator with a mechanism for its winding, the actuator being...
4283680 Electrical bridge balancing circuit  
An electric sensing circuit, typically a metal detector includes a bridge including inductors. The out of balance condition of the bridge is stored on a capacitor and a balancing signal is fed to...
4277750 Induction probe for the measurement of magnetic susceptibility  
The probe comprises two inductance windings mounted in opposition and conted to an a.c. generator, a measurement winding placed at right angles between the two inductance windings and a measurement...
4274054 Dual channel apparatus for detecting surface defects in elongate metallic members with liftoff compensation  
Inspection equipment for detecting defects in the surface of steel billets or other elongate members includes high-frequency energized eddy-current surface scanning probe which transmits signals...
4270545 Apparatus for examining biological bodies with electromagnetic fields  
The primary field generated by a transmitting loop or coil energized with a AC current induces secondary currents within the body which in turn generate a secondary field. The secondary field is...
4267508 Apparatus for non-contact measurement of distance from a metallic body using a detection coil in the feedback circuit of an amplifier  
An apparatus for non-contact measurement of the distance or gap between a detection coil and a metallic body arranged in an opposing relation with the detection coil, includes a differential...
4258319 Surface defect detecting apparatus for use with rotating circularly shaped metallic material  
The surface defect detecting apparatus for rotating cylindrical metal pieces which move in a lengthwise direction relative to a sensor block, has a plurality of eddy-current flaw detecting coils...
4255709 Device for providing an electrical signal proportional to the thickness of a measured coating with an automatic range switch and sensitivity control  
A device for measuring the thickness of coatings, wherein a thickness gauge is electrically coupled to a circuit intended to convert the electric signal at the output of said thickness gauge into...
4247818 Automatic sensitivity adjustment apparatus for calibration of a non-destructive inspection instrument  
The present invention is an automatic sensitivity adjustment apparatus for calibration of a nondestructive inspection instrument with a reference standard. Calibration is performed by setting the...
4237419 Method and apparatus for non-destructive testing using a plurality of frequencies  
A method and device for nondestructive testing of articles using the eddy principle current and multifrequency technique. The characteristic feature is that the measurement is generally independent...
4236093 Speed insensitive wheel detector  
An apparatus for detecting the presence and/or direction and/or velocity of a moving ferromagnetic element is provided. A sensing coil is placed in coupling relationship with a bi-stable...
4215310 Magnetic testing method and apparatus having provision for eliminating inaccuracies caused by gaps between probe and test piece  
A method and apparatus for electromagnetic testing of magnetic and/or electrically conductive materials. The apparatus includes the usual test probe which carries excitation and pickup coils and is...
4210866 Linearizing circuit for a non-destructive testing instrument having a digital display  
A linearizing circuit is provided for a non-destructive testing instrument having circuit means developing a DC voltage having a non-linear relationship to units of measurement or of conductivity...
4194149 Method for generating the eddy current signature of a flaw in a tube proximate a contiguous member which obscures the flaw signal  
A method for deriving the eddy current signature of a flaw in a tube proximate a contiguous member which is obscured in the composite signature of the flaw and contiguous member by subtracting from...
4193028 Eddy current instrumentation circuitry for distinguishing flaw signals from spurious noise signals  
An electronic circuit to be used in conjunction with eddy current non-destructive flaw detection instrumentation for distinguishing from noise or other undesirable signals a flaw signal having a...
4191922 Electromagnetic flaw detection system and method incorporating improved automatic coil error signal compensation  
An electromagnetic flaw detection system and method having automatic dynamic error balancing is disclosed. The system includes means for producing an alternating electromagnetic field and for...
4146837 Apparatus for detecting and recording surface and internal flaws  
The proposed structural flaw detector is intended for nondestructive testing of continuously moving electrically conducting products, e.g. aluminum, copper and other rods, and comprises two eddy...
4123708 Method and apparatus for eddy current inspection of hot test pieces with means to cool the detector and to purge the test path of contaminants  
An eddy current flaw detection apparatus which is particularly adapted for inspecting articles at elevated temperatures. A plurality of detectors are supported about at least a portion of a...
4116057 Pendulous induction compass transmitter with means to compensate for heading errors in turns due to the vertical component of the Earth's magnetic field and due to two cycle error  
The invention relates to an apparatus for compensating the output of a pendulous induction compass transmitter to eliminate heading errors during turns due to the vertical component of the Earth's...
4095469 Temperature measuring apparatus  
An apparatus for measuring the temperature of a metallic body in a non-contact maner includes an electronic circuitry for measuring a change in the impedance of a detecting coil arranged oppposite...
4087749 Method and apparatus for normalizing the outputs of sequentially scanned magnetic flaw detectors  
A method and apparatus for detecting flaws in conduits or the like which prises positioning an annular array of Hall-effect devices transversely around the conduit, applying an electric current to...
4079312 Continuous testing method and apparatus for determining the magnetic characteristics of a strip of moving material, including flux inducing and pick-up device therefor  
Continuous testing apparatus for determining the magnetic characteristics of a strip of moving material including a flux inducing and pick-up device to induce a quantity of flux into the material...
4074186 Conductivity measuring instrument having linearization means and a digital read-out  
Conductivity measuring instruments are provided in which a test coil is supplied with alternating current and a detector responds to the voltage across the test coil to develop an analog voltage...
4071818 Magnetostrictive position indicator  
The position of a movable member is measured without the establishment of physical contact with such member. A magnetic field generator, which provides a localized field of special geometry, is...
4061960 Apparatus for providing regulated direct current to magnetizing coils for non-destructive magnetic testing  
An apparatus for providing regulated direct current to magnetizing coils of a non-destructive magnetic testing apparatus for detecting welding defects in pipe, which includes a variable output...
4059798 Method and apparatus for measuring the current flowing in a workpiece  
Magnetic cores of clamp-on type current measuring devices having a Hall-effect device for measurement of D.C. currents are provided with stabilizing coils which are periodically energized to...
3991361 Semi-automatic compass calibrator apparatus for a vehicle mounted flux gate compass system to cancel out effect of local magnetic disturbances  
Method and apparatus for determining and applying a feedback current to the two sense windings of a vehicle mounted flux gate compass in order to provide a compensating magnetic field to cancel out...
3978399 Integrating fluxmeter with input current compensation to cancel drift  
The integrating fluxmeter disclosed herein employs a second electronic integrator which operates during the intervals between test periods to adjust a compensating bias current, applied to the main...
3974442 Surface defect probe and dual channel apparatus with liftoff compensation  
Apparatus for detecting surface defects in steel billets comprises an h.f. energized eddy current probe for scanning over the surface of the billet and a dual channel receiver responsive to signals...
Matches 401 - 450 out of 506 < 1 2 3 4 5 6 7 8 9 10 11 >