Abstract: A method for testing a magnetizable workpiece for flaws by the magnetic particle inspection method wherein a coating of finely divided, hydrophobic particles is electrostatically applied onto the surface of a workpiece to be tested after which an aqueous suspension of magnetizable particles is applied over the resulting coating. The magnetized workpiece is then inspected for deposits of magnetizable particles which have become lodged in the flaws. The hydrophobic nature of the coating repels the water from the suspension, and permits the indications to appear promptly after application of the magnetizable particle suspension.

Abstract: A standard specimen for calibrating an ultraviolet scanning system of the type used to detect surface flaws in workpieces by penetrant testing including a piece of glass which has the characteristic of emitting fluorescent radiation upon excitation by ultraviolet light, and a heat conductive carrier element rigidly supporting the piece of glass therein. The standard specimen provides a means for confirming instrumentation stability despite changes in temperature.

Abstract: A method and composition for detecting surface flaws in workpieces by means of the penetrant inspection process, the invention being concerned with an improved dry developer composition for use in such process, the developer containing substantial amounts of pentaerythritol, usually in combination with a finely divided inert powder.

Abstract: A method and apparatus are provided which are based upon a discovery that regardless of the type of ferromagnetic material of a part and its shape, there is a certain direct, uniform and constant relationship between the level of magnetization required for satisfactory testing by the magnetic particle method and the response which is obtained from an eddy current instrument which has been properly calibrated and which is used under proper conditions. After removal of scale from a surface portion of a part and after demagnetization of the part, a probe of the eddy current instrument is simply placed against such surface portion and the part is magnetized at a level which produces a certain target eddy current indication. The instrument may be readily calibrated through the use of a test block which has a milled slot of a certain size. Preferably, the probe is of a crossed coil type permitting a rapid scanning operation with respect to a plurality of surface areas of a part of irregular shape.

Abstract: A method for non-destructive testing for flaws on the surface of a workpiece which includes the step of applying a penetrant composition including a fluorescent dye in a liquid vehicle onto the surface to permit the penetrant to become trapped in the flaws and then removing excess penetrant from the surface while leaving penetrant entrapped in such flaws. A remover is then applied to the surface, the remover composition including a solvent, at least one surface active agent which serves as an emulsifier for the liquid vehicle of entrapped penetrant, and a fluorescent material which is more readily soluble in the liquid vehicle of the penetrant than it is in the solvent. Upon contact of the entrapped penetrant with the remover, the fluorescent material from the remover is preferentially absorbed in the penetrant vehicle entrapped in the flaws thereby enhancing the fluorescent indication provided by the entrapped penetrant.

Abstract: Pipeline inspection apparatus is provided including a camera unit and associated illumination means, preferably a strobe flash unit, for recording on photographic film the images of internal surface portions of a pipe for detection of defects. The camera unit is moved longitudinally within a pipeline by a drive unit which preferably includes electric motors energized from a self-contained battery unit. Important features relate to means for automatically reversing the drive of the apparatus after it has travelled a predetermined distance and to mechanical features for facilitating movement of the device through bends and the like.

Abstract: 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 or some other characteristic measure. A plurality of linearizing stages are provided each including an adjustable resistance connected between a reference voltage source and an output line when the potential of the output line is between the reference voltage and one limit of the DC voltage. Preferably, an analog switch is provided in series with the adjustable resistance and is controlled from an operational amplifier, with a second operational amplifier being provided having an output connected through the analog switch and the adjustable resistance to the output line. The circuit is very accurate and reliable and is readily adjusted by a method wherein the resistances are adjusted in accordance with reference voltages in a certain sequence to obtain accurate adjustment with no juggling operation.

Abstract: An ultrasonic system for detection of defects is provided including a pulse-echo instrument having a cathode ray tube on which an A-scan visual indication of flaws is produced and including a doppler circuit arranged to produce a doppler signal in an audible range in response to movement of a transducer relative to defects in a pipe seam or other region being investigated. The doppler signal is applied to earphones, permitting the existence of defects to be reliably determined audibly, after which the defects may be more carefully studied through the visual indications on the cathode ray tube. The doppler signal is also recorded on one track of a magnetic tape with operator's comments being recorded on a second track of the same tape.

Abstract: An X-ray tube having internal shielding and producing less external stray radiation comprising an evacuated envelope, an X-ray generating target within the envelope, an electron gun positioned within the envelope to direct a stream of electrons at the target, a window arranged to direct the resulting X-rays through the envelope, high density attenuating means located within the envelope and substantially surrounding the target to attenuate high energy photons which do not exit through the window means, and a lower density metal covering about at least a portion of the high density attenuating means in order to reduce the intensity of secondary X-ray emission from the high density attenuating means.

Abstract: Demagnetizing methods and apparatus are provided in which a pipe, tube, rod, bar or other elongated part to be demagnetized is moved through the coil assembly to which pulses of current are applied to produce magnetic field pulses of alternating polarity and of substantially constant durations and magnitudes with a substantially constant repetition rate, each current pulse being effective to produce by the end thereof a reversal of the magnetic field in all portions of the part positioned within the confines of the coil assembly and immediately adjacent thereto, the part being moved longitudinally through the coil assembly at a velocity sufficiently low as to effect demagnetization of all portions of the part. The duration of each current pulse is at least 50 milliseconds and most preferably on the order of 0.5 seconds and the velocity of movement is preferably less than two feet per second.

Abstract: A method and apparatus for calibrating a gamma ray inspection system for measuring the wall thickness of a tubular product such as a pipe or the like, the system including a gamma ray beam generating station, means for conveying a tubular product axially past the gamma ray beam, the gamma ray generator being rotated during the axial movement of the tubular product, means for detecting the amount of attenuation of the gamma rays passing through the tubular product, and a calibration block having a first portion with a thickness corresponding to twice the nominal wall thickness of the tubular product to be inspected, and a second portion having a thickness corresponding to a predetermined amount less than the nominal wall thickness. Means are provided for selectively introducing the first portion and the second portion of the calibration block into the gamma ray beam to enable the operator to calibrate the equipment and to be able to detect tubular products which are defective in terms of thickness.

Abstract: A storage system is provided in which digital numbers are read into a memory by periodically sampling a pair of analog input signals and in which the memory is scanned in timed relation to the signal sampling and also in timed relation to the scanning of a cathode ray tube screen in a raster pattern, the scanning spot being brightened when a stored digital number is detected.A pair of digital-to-analog converters are used both in sampling and for raster scanning. In sampling, the outputs thereof are compared with the input signals to control analog-to-digital logic circuits and the inputs thereof are connected through multiplexers to the output of the analog-to-digital logic circuits which operate as successive approximation registers. In raster scanning, the inputs of the digital-to-analog converters are connected to counter sections driven from a high frequency clock one being operative to develop a sawtooth signal to generate a sweep line and the other being operative at a field or frame rate.

Abstract: An X-ray unit is provided having a self-contained high voltage supply including a pair of capacitors charged through diodes from a pair of transformer secondary windings and connected in series through the windings to the anode and cathode of an X-ray tube. Switching means are provided for operation either in a first mode in which the alternating voltages across the secondary windings are in phase and in which the output voltage is equal to the sum of the DC voltages across the capacitors to be substantially constant, and a second mode in which the alternating voltages across the secondary windings are out of phase and in which they are added to produce a pulsating output voltage having a peak value which is approximately double that of the substantially constant voltage obtained in the first mode of operation.

Abstract: 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 which is applied to a linearization circuit to develop an output voltage as a linear function of conductivity, the output voltage being applied to a digital read-out unit. As a function of conductivity, the analog voltage is single-valued, preferably with no more than a gradual slope change over a wide range of conductivity values. In one embodiment, a high impedance is provided in series with the test coil, the detector is a phase detector operated to respond primarily to the inductive component and linearization circuit is of a diode-function type. Alternatives are in the use of a phase-to-voltage type of detector and in the use of a digital type of detector and in the use of a digital type of linearization circuit.

Abstract: A magnetic testing device is provided in which a magnetic recording tape or paper is wrapped around the outside of a tubular pressure member of elastomeric material which is disposed between two circular end plates which form pole portions of a yoke having a central core extending between the end plates and having a coil wound thereon with a copper shield being disposed around the outside of the coil. The device is disposed in a pipe or the like and compressed air is supplied to inflate the pressure member and press the magnetic tape paper into intimate contact with the interior surface of the pipe while an AC current is supplied to the coil to apply a magnetic field to the pipe and to record a magnetic field pattern on the magnetic tape or paper.

Abstract: The invention relates to a system and method of testing small cylindrical parts wherein a part is journalled for free rotation about a substantially stationary axis with one side of the part being frictionally engaged with a magnetic tape moved longitudinally to rotate the part and to transfer a magnetic flux pattern at the surface of the part to the tape. Important features relate to the provision of engagement means for obtaining non-skid intimate contact between the tape and the part, to the application of a biasing field to the tape at the area of interengagement between the tape and the part and to the manner of supporting the part.

Abstract: Automatic balancing circuits are provided for non-destructive testing systems such as eddy current systems in which an unbalance of a probe circuit including a test coil produces undesired deviations from a null indication. Error signal components are generated from a probe circuit output signal, stored in storage means and then applied in a balancing direction to cancel the effect of the unbalance of the probe circuit. Preferably, the error signal components are generated by a pair of quadrature phase detectors and the storage means comprises either a capacitor or the combination of digital storage and digital-analog converter means. The balancing is performed either automatically, with a delay in the storage operation, or by operation of a switch means between a sample or null condition in which the error signals are stored and a hold condition in which the stored error signals are applied.

Abstract: An improvement in the method of inspecting a test piece for surface flaws in which an oily based dyed penetrant is applied to the test piece and subsequently the test piece is treated with an emulsifying agent to remove excess penetrant from its surface. The improvement is concerned primarily with using an aqueous soap solution as the emulsifying agent, the soap being a water soluble compound of a fatty acid containing from 12 to 20 carbon atoms. The emulsified penetrant is removed by rinsing with an aqueous solution, the emulsified penetrant, residual soap and rinse water are collected and then the collected liquid is reacted with an aqueous solution of a water soluble calcium or magnesium salt to thereby form a readily filterable curd containing the oily penetrant and a substantially dye-free supernatant liquid layer which can be totally separated from each other.

Abstract: A method for detecting surface discontinuities in a part which comprises applying a non-water miscible fluorescent penetrant to the part to permit the penetrant to enter and become lodged in surface discontinuities, applying an emulsifying agent to the part to emulsify excess penetrant, washing the part with water to remove the emulsifying agent and emulsified penetrant while leaving penetrant lodged in the discontinuities, and thereafter applying particles of a dry hydrophobic developer over the part so that upon removal of excess developer, the part may be inspected for penetrant exuded out of the discontinuities and into the hydrophobic particles.

Abstract: Radioisotope camera lock, locking the source isotope in a safe, shielded position in the camera when not in use. The lock prevents the source isotope from being moved to an operative position outside of the camera, unless intentionally released by a key and reverse movement of source pigtail. A hollow lock casing is secured to and has communication with the interior of the radioisotope camera. The source isotope is at the end of a source pigtail and is cranked or pushed from the camera and pulled back into the camera by the cranking mechanism. A stop on the source pigtail cooperates with a lock spool movably mounted in the lock casing. A lock lever pivoted in the lock casing is provided to hold the source isotope in a shielded condition within the camera upon moving the lock to its locked condition. The locking arrangement is such that the source isotope will automatically be trapped in the camera as fully withdrawn into the camera prior to manual locking.