Abstract: A vacuum ultraviolet and x-ray light source based on spontaneous anti-Stokes scattering from atomic population stored in a metastable level is described. The source has a maximum brightness, attained as the media approaches two-photon opacity, equal to that of a blackbody at a Boltzmann temperature characteristic of the population of the metastable level. The source may have high resolution, picosecond time scale, and on a pulsed basis is brighter than other laboratory vacuum ultraviolet light sources. Short wavelength lasers pumped by said source are also described. The lasing atomic species can be separate from or combined in the same envelope with the light source atomic species. Use of the source for spectrographic applications is also described.

Abstract: Apparatus for detecting defects such as fissures in the ferrous metal of elongated workpieces such as pipe may take the form of wall thickness and material continuity inspection apparatus that is located at an inspection site, with the inspection site being provided to receive an elongated metal workpiece such as a section of drill stem. A movable magnet support structure is located at the inspection site and carries a magnet and coil assembly in movable shoe means that is capable of engaging the outer periphery of the workpiece and establishing a predetermined spaced relationship between the workpiece, the magnet and the coil. The magnet support shoe, together with the magnet and coil, are movable in helical manner about the workpiece, causing the shoe to traverse the entire outer periphery of the workpiece during a single inspection pass.

Abstract: A device for measuring the intensity and direction of external magnetic fields comprising a differential ferroprobe, a recording unit and a unit for feeding field windings of the ferroprobe, the latter unit including a thyristor, a capacitor one terminal of which is connected to one terminal of a power source and to one lead of the field windings, the other terminal of the capacitor being connected to a cathode of the thyristor and an anode of a diode whose cathode is connected to the other terminal of the power source and a control electrode of the thyristor, the anode of the thyristor being connected to the other lead of the field windings.

Abstract: A self inverting gauging system for such parameters as capacitively sensed distance or inductively sensed resistivity in which the sensor provides an output inversely varying with the dimension of interest. The gauge typically includes a dual slope integrator responsive to a reference value on the up integration and to the sensor output on the down integration. The interval of the down integration necessary to reset the integrator to the original value varies directly, rather than inversely, with the dimension of interest and is typically provided as the digital output indication of a counter. In the application to resistivity gauging, the up integration reference signal is preferably provided by the output of a thickness gauge such that the ultimate counter display represents element resistivity compensated for thickness.

Abstract: A detector for magnetically detecting flaws on the inner surface of a pipe of magnetizable material comprises a magnetizing assembly having exciting magnets and movable longitudinally along the interior of the pipe and a detecting assembly movable longitudinally along the exterior of the pipe. The magnetizing and detecting assemblies are opposite and close to each other through the wall of the pipe and movable longitudinally of the pipe in a synchronized manner to ensure highly accurate flaw detection.

Abstract: 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 placed against a test piece of magnetic and/or electrically conductive material. The invention eliminates inaccuracies in the test caused by variable distances or gaps between the probe and test piece surface. Properties of the test pieces are determined by applying a controlled alternating drive current to the excitation coil so as to produce a predetermined a-c voltage in the pickup coil and measuring the drive current applied to the excitation coil when the time-integral of the voltage induced in the a-c pickup coil corresponds to zero magnetic flux in the gaps.

Abstract: Multi-tipped probe for testing integrated circuit elements, featuring, in various aspects, contact elements each resiliently biased in a rest position with a portion of itself spaced from a support and movable to an operating position against the support, the element tips being coplanar in the operating position; and contact elements having end portions oblique to an axis of the support and having peripheral edges at their ends for contacting the lead with the axis parallel to the lead.

Abstract: This invention provides an apparatus for adjusting the scale and range of D'Arsonval pointer-type meters providing an uncluttered accurate readout particularly adapted for compact hand-held meters. Display wheels imprinted with numerals for a plurality of different scales are provided enabling the user to set, by manual rotation of a drive gear engaging a ring gear one of a plurality of desired ranges. The invention also provides for the simultaneous automatic selection or interconnection of circuit elements for driving the meter movement in accordance with the selected range.

Abstract: A device for testing phase inversion of a circuit includes a signal generator having an assymetrically shaped positive phased test signal output electrically connected through a buffer circuit to the input of the circuit under test. A differentiator circuit electrically connected to the output of the test circuit, produces in response to the test circuit output, rectangular pulses whose amplitudes are proportional to the slopes of the test waveform. The differentiated output signals are isolated into positive and negative signals by a plurality of peak detectors whose outputs are fed to a summing amplifier. The summing amplifier amplifies the difference between the positive and negative isolated peak voltages and in turn drives a polarity indicating device which was previously calibrated to indicate a positive or negative polarity as either a phase or non-phase inversion. An alternate mode of measuring pulses directly and bypassing the differentiator is also provided.

Abstract: A voltage indicating meter is connected between the outputs of two high impedance operational amplifiers, the first of which receives an input signal to be measured through a range setting resistance dividing network and having a gain which can be set to one of a plurality of different values. A zero control network applies a bias voltage to the inverting input of the second operational amplifier for zeroing the meter. The non-inverting input of the second amplifier can be connected either to the output of the first operational amplifier or to a source of reference potential. When, during operation, the non-inverting input of this amplifier is connected to the source of reference potential, the one terminal of the meter is clamped to the bias level and the other receives a voltage proportional to the voltage of given polarity being measured and the meter needle swings in a given direction.

Abstract: A tunable source of infrared radiation is obtained by irradiating an assemblage of Raman active gaseous atoms or molecules with a high intensity pumping beam of coherent radiation at a pump frequency .omega..sub.p to stimulate the generation of Stokes wave energy at a Stokes frequency .omega..sub.s and to stimulate the Raman resonant mode at the Raman mode frequency .omega..sub.R within the irradiated assemblage where the pump frequency .omega..sub.p minus the Stokes frequency .omega..sub.s is equal to the Raman mode frequency .omega..sub.R. The stimulated assemblage is irradiated with a tunable source of coherent radiation at a frequency .omega..sub.i to generate the output infrared radiation of the frequency .omega..sub.0 which is related to the Raman mode frequency .omega..sub.R and the input wave .omega..sub.i by the relation .omega..sub.0 =.omega..sub.i .+-..omega..sub.R. In one embodiment the interaction between the pump wave energy .omega..sub.p and the tunable input wave energy .omega..sub.

Abstract: The water content of electrically non-conductive powders, granulates, pastes and fibrous materials may be measured on the basis of microwave absorption. A frequency-modulated microwave oscillator supplies a closed multimode measuring resonator charged with the sample in a transmission arrangement. The sample charged into a container almost completely fills the multimode resonator. The sample container is rotatable about its longitudinal axis. A substantial homogeneity of the field distribution in the sample is thus obtained so that even in the case of variations in the bulk density, accurate measurements are still possible.

Abstract: Apparatus for detecting possible changes or variations in the dimension of an air gap of a running electric rotary machine during operation thereof. Detector coils are each accommodated within respective slots formed in the stator core of the machine, the coils being geometrically separated from one another at an angular distance corresponding to the distance between poles or its integral multiple. The detector coils are electrically connected in series with each other to produce a voltage for detection. The detector coils are so connected that the fundamental waves of the voltages induced in two detector coils will cancel each other and a synthesized value of higher harmonics induced in both detector coils is picked up as the detection voltage signal. The number of slots of the rotor of the electric rotary machine is predetermined to a limited number in order to get a detection signal of higher quality.

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: Disclosure is made of a position sensor comprising a plurality of inductance coils with open magnetic circuits. One of the coils has two pairs of poles. The position sensor further includes a shunting element designed for movement along the axis of the coils and connected to a moving body whose position is to be found. The shunting element has groups of holes arranged along its axis. In each group, the holes are arranged along the perimeter of the shunting element. The interpole distance of the coil with the two pairs of poles is specially selected with due regard for the diameter of the holes and the interhole spacing to ensure a high accuracy of the measurements.

Abstract: In a circuit arrangement for measuring currents at high potential, a capacitor, charged in accordance with the current to be measured, is shunted by a light emitting diode which generates a light pulse sequence with a frequency proportional to the current. In series with the diode is a switching element with a control terminal, to which the output of a control device is connected. The input of the control device is connected to a threshold arrangement disposed parallel to the capacitor and the supply terminals of the control device are connected to the capacitor.

Abstract: An interchangeable test head for a vacuum fixture for testing a loaded planar test member. The test head includes support means comprising a planar support surface. A platform is in opposed relation to the planar support surface and has a planar test member surface. Resilient seal means is affixed to the platform and is flared outwardly around the perimeter of the platform to a free edge which engages and forms a vacuum seal with the planar support surface thereby providing a vacuum chamber between the platform and the support means. Stop means limits the deactuated position of the platform so that the entire free edge of the seal means remains in engagement with the planar support surface. Vacuum in the chamber causes the platform to move along the path from the deactuated position to the actuated position. A plurality of spaced spring probes is mounted on the support means. A plurality of openings is provided through the platform for drawing a test member against the spring probes.

Abstract: An automatic eddy current inspection system for discrimination of defects in elongated parts made of conducting materials comprises an alternating current generator connected in series to an amplitude selector via a differential encircling eddy-current transducer and a detector. The amplitude selector has two selection levels. The system also comprises a signal analyzer with a controllable switch and the following counters: a counter for determining the length of long cracks; a minor defects counter; a major defects counter; and a counter for determining the length of tested parts. The outputs of the counters are connected to the inputs of a sorter having its outputs connected to quality grade indicators. The controllable switch of the signal analyzer has its control input connected to the output of the amplitude selector which corresponds to a higher selection level.

Abstract: The level of the interfacial boundary between two liquids having different dielectric constants is located by means of a detector in which two parallel sectional members constitute external capacitor plates supported by a metallic base plate and in which small metallic plates encased within an electrically insulated central upright member constitute central capacitor plates. The assembly thus forms a plurality of capacitors, the plates of which are immersed in at least one of the liquids. Each capacitor forms part of an oscillating circuit connected to electronic means for effecting a comparison between the oscillation frequency and a reference frequency.

Abstract: A mercury vapor lamp having a light transmissive envelope defining an arcuate capillary plasma cavity. A mounting base secured to one end of the envelope has a configuration which is geometrically unique with respect to the position and spatial orientation of the plasma cavity. A mounting block and clamping arrangement have a configuration complementary to that of the lamp base so as to receive and releasably secure the lamp base and, therefore, the plasma cavity in a fixed predetermined position and orientation relative to its operating environment. The lamp is energized by means of an electrical potentional applied to electrodes in the plasma cavity or by reactance coupling an r-f power source to the cavity.