Abstract: There is described a programmable gas flow control apparatus for use in atomic absorption spectroscopy. Essentially, an all pneumatic system is described which provides for a predetermined flow of fuel and oxidant to the burner. The invention compensates for the variation in oxidant flow due to nebulizer adjustments by adjusting the oxidant flow to the auxiliary inlet of the burner. The invention utilizes a pneumatic computing relay which senses the oxidant flow to the nebulizer and simultaneously adjusts the flow to the auxiliary inlet so that the total flow of oxidant satisfies the predetermined optimum rate. The constant monitoring of the nebulizer line by the computing relay allows for continual adjustment of the oxidant flow to offset subsequent adjustments.

Abstract: In order to obtain shorter exposure time and to obtain a longer life in x-ray lithography apparatus, an x-ray target made of tungsten is utilized and the apparatus operated to generate the tungsten M-line, this line being at a wavelength which will be absorbed by the resist normally used in lithography. To develop the resist, which was initially designed for use in an electron beam lithography, a developing method is used in which a initial short development with a high concentration is first carried out followed by a longer, full development with a concentration which is approximately the lowest at which complete development will take place.

Abstract: Atomic absorption spectrometer sample supply apparatus for producing a gaseous sample for analysis and for transferring the sample to the atomic measuring cuvette. The sample supply is in a sealed vessel and, by directing the flow of a pressurized inert gas, the sealed sample vessel is first purged of contaminating air, a volatilizing reagent is forced by inert gas pressure into the sample, and a small specimen of the gaseous sample is transferred by gas pressure into the cuvette inlet tube.

Abstract: Method and apparatus for preparing a liquid sample for combustion and analysis in an elemental analyzer. In order to avoid damage to the quartz combustion tube and ladle by molten aluminum, the sample is placed in an aluminum foil vial which is crimped and placed in turn in an open ended capsule of nickel or other non-reactive metal. The capsule is then distorted by a novel encapsulator to partially obstruct the open end and retain the liquid sample vial therein during the combustion process.

Abstract: Inaccuracies resulting from measuring the internal temperature of absorption spectrophotometer graphite tube furnaces by pyrometric measurements of a spot on the external surface of the graphite tube are overcome by a novel arrangement in which the pyrometer detector measures the interior through the tube end and at an angle that permits a view of the entire interior length without interfering with the spectrophotometer sample beam.

Abstract: An improved method and apparatus for attaching a target to the cathode of a cathode sputtering system is disclosed which includes a ferromagnetic retainer which releasably clamps the target to the cathode by virtue of its attraction to existing permanent magnets in the cathode assembly. An optional ferromagnetic ring may also be provided around the periphery of the target to further hold the target to the cathode assembly.

Abstract: An automatic sampling apparatus for withdrawing samples from a continuously flowing liquid for analysis by a flameless atomic absorption spectrometer includes a sample vessel which, at predetermined times, receives pumped samples of the liquid to be tested, a neutral dilutant liquid, or a calibrated liquid for recalibrating the spectrometer system. A probe having a pipette-like tip is mechanically actuated to dip into the sample vessel and an intake and dispensing pump connected to the probe draws a small sample into the probe tip whereupon the probe mechanism lifts and rotates the probe and inserts the tip into the graphite atomizer tube of the atomic absorption spectrometer. The probe mechanism then returns the probe where it is first flushed with a flushing liquid pumped through the probe and is then returned to the sample vessel to draw the next test sample.

Abstract: An adjustable pitch, zero backlash, rotary-to-linear-motion converter particularly adaptable for the precision positioning of linearly movable light weight mechanisms. The spherical bearing ends of three or more dumbbell-shaped rollers, in an interference fit between a rotatable shaft and the inner surface of a cylindrical sleeve, are partially enclosed in end cages which are clamped together but which may be adjusted so that the parallel roller axes are offset from the shaft axis whereby rotation of the shaft will provide rectilinear movement to the sleeve.

Abstract: Disclosed is a sample feeding apparatus having a housing defining first and second chambers sealed one from the other and a needle movable longitudinally with respect to the housing. The first and second chambers continuously receive carrier and purging gases respectively through suitable conduits. The needle has an opening normally in communication with the second chamber for continuously purging the needle. Upon application of a sample vessel to a member telescopically received about the housing, the needle is displaced through a seal into the first chamber. Carrier gas is thus provided through the needle into the head space of a sample vessel and the sample will flow to the injection block of a gas chromatograph in response to pressure compensation between the injection block and head space. Upon withdrawal of the sample vessel from below the sampling apparatus, the needle is spring returned to its initial position preventing carrier gas from flowing from the first chamber through the needle.

Abstract: A method and circuitry for the pyrometric measurements of temperatures of graphite tube atomizers for flameless atomic absorption spectroscopy over very wide temperature ranges of, for example, 100.degree. C.-2700.degree. C. independently of the emission factors of the various graphite tubes. The heated tube is measured by a radiation pyrometer which has a very wide temperature measuring range but with an accuracy that is affected by tube emission factors and is also measured by an independent measuring system which is accurate independently of the emission factor at some particular elevated temperature. When the graphite tube reaches that elevated temperature, the output signals of both systems are mixed to produce an error signal that is used to accurately calibrate the pyrometer circuitry. Since it has been found that the percentage variation of emission factor is independent of graphite tube temperatures, the pyrometer will now produce accurate measurements over a very wide temperature range.

Abstract: A valve having a plunger with opposite end sections of equal diameter, a control section of lesser diameter and a valve member. One end section extends from the inlet chamber through a seal to the exterior of the valve, and the other end section extends from the outlet chamber through a seal to the exterior of the valve. The inlet and outlet chambers are connected by a central bore having a diameter equal to that of the plunger end sections. The central section of the plunger extends through the central bore. The valve member seats against one end of the central bore to close the valve. Because of the equal diameters of the axial bores of the end sections and the central bore, the force exerted on the plunger by fluid pressure in the valve are balanced regardless of the plunger position, i.e., open, closed, or at any intermediate position.

Abstract: At least two posts are extended from a deformable specimen and individual force couples are applied through each post to vary the configuration of the specimen. Specific embodiments are disclosed wherein the specimen is a flexible mirror in an optical system; in one form thereof, parallelogram linkages apply the force couples to the posts, and in another form thereof, extension assemblies are mounted between the posts which are each actuated by a remotely disposed actuator through a flexible drive.

Abstract: A spectrophotometer detector cell assembly having improved sensitivity, has a cell defined by a bore through a body and closed at the ends by radiation transparent windows with inlet and outlet passages through the body to the bore, so that radiation passed through the sample fluid flowing through the bore is detected by a photodetector. The body, which is made of a thermally conductive material, is a large thermal mass is relation to the volume of the cell and a tubular inlet conduit, also made of a thermally conductive material, wraps around the body and connects to the inlet passage so that fluid flowing into the bore will tend to reach a stable temperature due to the heat sink effect of the body and conduit thereby stabilizing the refractive index of the fluid in the bore and enhancing the sensitivity of the photodetection.

Abstract: A flame spray powder comprising particles having a core of nickel, iron, copper, cobalt or alloys thereof coated with a binder containing discrete particles of aluminum and substantially pure nickel. The core material should be present in amounts of 70-98, and preferably 80-94, weight percent of the total metal content of the powder. The core particles should range in size between -60 mesh and +3 microns, and preferably -100 mesh and +400 mesh. The core material is most preferably nickel, and the coating may, in addition to the aluminum and nickel, contain molybdenum.

Abstract: A graphite tube atomizer for flameless atomic absorption spectroscopy includes a graphite tube disposed to permit passage of a measuring beam therethrough. The graphite tube is engaged at opposite ends by annular contact pieces which are coupled to a source of electrical current. The contact pieces are supported in housing portions which serve to surround the graphite tube and provide a chamber into which cooling gasses can be admitted. The cooling gasses also serve to reduce deterioration of the graphite tube. The housing portions are selectively movable either toward or away from each under the power of a drive mechanism. The housings may be urged by the drive mechanism toward each other so the contacts mounted thereon are in selectable pressure engaging contact opposite ends of the graphite tube.

Abstract: Power is applied to an electrical element in maintaining a thermal system at stabilized conditions and a feedback signal is derived to control the electrical input to the heating element by linearly combining functions of the current through the heating element and the voltage drop thereacross respectively. In one embodiment, each of the linearly combined functions in the feedback signal can be varied independently to change the stabilized conditions of the thermal system, while in another embodiment a microprocessor is incorporated to provide such variation for a sequential range of stabilized conditions.

Abstract: Method and apparatus for plasma flame-spraying coating material onto a substrate by means of passing a plasma-forming gas through a nozzle electrode, passing an arc-forming current between said nozzle electrode and a rear electrode to form a plasma effluent, introducing coating material into the plasma effluent, passing the plasma effluent axially through a wall shroud extending from the exit of said nozzle electrode and forming a flame shroud for the plasma effluent at least within the wall shroud.

Abstract: Heat is applied to atomize the residual liquid from a sample transfer probe on which at least the tip is fabricated of heat resistant material. In one embodiment, the sample transfer probe is disposed within an atomic absorbtion spectrometer having a hollow graphite furnace that includes a port through which the sample is dispensed for atomization in the furnace. The probe tip in this embodiment is configured to extend into the graphite furnace while making thermal contact therewith so that the sample residue on the probe tip is atomized simultaneously with the sample in the furnace. Inert gas is connected to the sample transfer probe through a control valve to flush the atomized sample residue from within the probe tip in still another embodiment.

Abstract: Apparatus for controlling the width of an adjustable slit in response to the product of two variable functions, one of which is programmed, which includes at least one adjustable optical slit; slit width programming apparatus for producing a first displacement that is a logarithmic function of the instantaneous slit width conforming to a predetermined program; antilogarithm generating elements for producing a second displacement that is the antilogarithm of the first displacement; a phase adjusting mechanism for controlling the phasing between the first displacement and the second displacement; slit width selection apparatus operative on the phase adjusting mechanism for controlling the phasing in accordance with a given slit width selection; and actuating elements responsive to the second displacement and operative on the optical slit for controlling its width.

Abstract: A device for automatically supplying liquid samples to analytical instuments having a support member; a sample source mounted on the support member; a calibration vessel holder mounted on the support member for carrying a plurality of vessels containing neutral or calibration solutions, said holder being movable in a stepwise manner; an intake tube mounted for vertical reciprocating motion corresponding to predetermined points of an operating cycle; and wherein the support member is movable to a first position wherein the sample source is disposed adjacent the intake tube and to a second position wherein one of the vessels in the vessel holder is disposed adjacent the intake tube.