Abstract: An improvement in a spectrophotometer of an improved apparatus for automatic initialization of the wavelength indexing function of the spectrophotometer. A drive mechanism drives the wavelength indexing movement of the spectrophotometer diffraction grating. The grating is initialized to a grating initialization position by physical opposition of a stop mechanism to the driving when a drive linkage reaches a drive linkage initialization position.

Abstract: An apparatus for transferring a portion of an image from the spherical focal surface of a telescope to a fixed viewing area. A spherical parallelogram type linkage has means for selectively positioning a mirror in the spherical focal surface of the telescope and constrains the mirror to move within the contour of the spherical focal surface of the telescope. The parallelogram type linkage includes means for transferring the image reflected by the mirror to a remote viewing area.

Abstract: There is disclosed a filter-grating monochromator for use in an optical analytical instrument. The monochromator is characterized by a simplified construction compared to prior art monochromators. Nevertheless, the monochromator includes features which retain the desired high accuracy, including a novel sine bar grating drive mechanism and filter change mechanism.

Abstract: The disclosed high resolution analog to digital converter circuit has an integrator circuit responsive to the unknown analog input. The integrator circuit is operated for a fixed period of time during which, on a periodic basis, a predetermined charge is dumped from the integrator circuit capacitor. A counter is incremented each time a dump occurs and the counter value at the end of the fixed period is related to the high order digits of the digital value for the unknown analog signal. A digital number corresponding to the output level of the integrator is determined by a successive approximation circuit both before and just after the fixed period. The difference between the two values determined by the successive approximation circuit is related to the low order digits of the digital value for the unknown analog signal.

Abstract: A multi-level arbiter for resolving multiple requests for access to a shared facility. The arbiter includes a plurality of loop arbiters, each including a polling circuit to test each of a plurality of units for a request for access to the shared facility. The first unit encountered by the polling circuit on each loop which has a request for service active is conditioned to utilize the shared facility as soon as the central arbiter grants the request for service to the loop. The central arbiter assigns priority among the loop arbiters.

Abstract: Disclosed is apparatus for automatically transporting liquid samples from sample vessels to the burner of a flame atomic absorption spectrometer or a flame photometer. A sample feed tube pivots between a first position with its end disposed in a sample feeding vessel for discharging, in sequence, sample liquid and a flushing liquid into the feeding vessel and a second position with its end in communication with a sample vessel. The sample feeding vessel has an upper opening, a bottom outlet, and a cavity between the outlet and opening having an annular convex interior surface to ensure accurate and repeated insertion of the sample feed tube into the sample feeding vessel when the sample feed tube is moved into its first position and full and complete discharge of the sample liquid into the sample feeding vessel. A control mechanism is provided to prevent discharge of the sample liquid from the sample feed tube unless and until the sample feed tube obtains its first position.

Abstract: The present invention includes an apparatus for measuring radiation from a sample. The apparatus includes means for axially focusing radiation from an excitation monochromator at the sample. The present invention further includes a novel sample cell holder useful with the fluorescent radiation measuring apparatus.

Abstract: Apparatus for detecting and/or determining the wavelength of coherent radiation in the presence of incoherent ambient radiation. The apparatus includes at least three unequal path interferometers with the radiation path length difference in each interferometer being substantially greater than the coherence length of the incoherent radiation, but substantially less than the coherence length of the coherent radiation, the average radiation path length in said three interferometers being different one from the others. The apparatus further includes detectors for detecting the radiation transmitted through each of the interferometers for generating signals corresponding to the radiation leaving each interferometer, and electronic processing elements to detect and determine the wavelength of the coherent radiation.A preferred form of interferometer is a Fabry-Perot etalon having a plurality of regions of different thicknesses.

Abstract: A fluid activated pump that is particularly well suited for use in analytic machines of the type that need to accurately meter quantities of sample solutions. The pump, which includes a pump piston driven by a power piston, is powered either hydraulically or pneumatically. Also included in the pump is a displacement adjustment piston, which is either hydraulically or pneumatically controlled, and which, through a suitable shaft-type linkage, can adjust the length of the power piston's stroke, and thus permit either a large or small displacement of the pump piston. The fact that the pump piston's displacement can be changed means that the pump of the present invention can more efficiently meter solutions into various desired ratios, and can reduce the chance of cross-contamination of sample solutions by dispensing a large amount of rinsing solution after dispensing a relatively small amount of sample solution.

Abstract: A recessed housing and cover are held together by self-tapping screws. The housing is provided with a half round extension having an inner diameter slightly larger than the outer diameter of the cable. The cable insulation is removed to about the middle of the extension and is held tightly to the extension and the assembly by means of two layers of heat shrunk plastic tubing. Wires from the cable to the pins of a multi-pin military type connector are contained within the recess. The military connector is provided with a surrounding flange which is held in engagement with a pair of outrigger bosses on the recessed housing. The recessed housing and the top cover are also provided with opposed flanges for engagement with the flange of the military type connector.

Abstract: A graphite tube assembly for use in the atomic absorption spectroscopic measurement of samples, particularly liquid samples, during the passage of a beam of radiation through a graphite tube is disclosed. The graphite tube assembly includes a graphite tube and a sample holding platform which are cooperatively adapted to allow the platform to be removed and reinserted, or exchanged with another platform, while maintaining a preselected orientation of the platform with respect to an inlet port extending through the wall of the graphite tube.

Abstract: An apparatus and method for coating a substrate. An electrically conductive substrate is placed in an electrolytic bath with the surface to be coated facing the anode. The cathode is placed near but not touching the other side of the substrate and an electric potential is applied to both electrodes. Means are provided to prevent electroplating of the cathode.

Abstract: Stray light produced in a monochromator by the diffuse reflection of the incoming light beam specularly reflected from the surface of the diffraction grating is practically eliminated by interposing a black glass "absorbent-reflector" in the path of the specularly reflected beam. The small percentage of radiation that is not absorbed by the absorbing glass is reflected to an opposite blackened wall which diffuse reflects an extremely small percentage of the beam back to the absorbent-reflector where a very negligible part is returned to the grating surface and eventually to the monochromator exit slit.

Abstract: Circuitry for recording and subsequently reading magnetic tape recorded binary data without tape flutter. The circuitry includes time base correction circuitry to assure a precise crystal controlled data output and a precise long-term data output speed to thereby assure against loss of data being transmitted from the system during a fixed time frame.

Abstract: Disclosed are methods and apparatus for concentrating a looked-for element from a solution for flameless atomic absorption spectroscopy. The tip of an electrode is dipped into a sample vessel containing the solution and an electric current is passed through the electrode and solution to electrodeposit the components of the solution on the electrode. The electrode with the electrodeposition is removed from the sample vessel and inserted into the graphite tube. The tube is then heated and the sample components electrodeposited on the electrode are atomized for analysis by the measuring beam of the atomic absorption spectrometer.

Abstract: Apparatus for injecting a selected one of a plurality of samples into a graphite tube atomizer of a flameless atomic absorption spectrometer. A sample dilutant or blank solution, a standard solution for calibrating the spectrometer, and each of a plurality of unknown sample solutions are continuously fed into separate overflow vessels mounted in a turntable driven by a servomotor and monitored by a suitable analog-to-digital encoder. Each of the vessels overflow into a common drain channel and the vessels are positioned by a control system so that a small sample from selected vessels that may contain an unknown sample, dilutant, or calibrating standard, is drawn by a pump into an intake tube. A servomechanism then repositions the tube into the graphite tube atomizer and the pump reverses to inject the solution into the atomizer.

Abstract: A sample feeding device includes a turntable driven by a servomotor and mounted on a carrier driven by a separate servomotor. The turntable servomotor and the carrier servomotor, as well as a movable intake tube, are controlled by a control device.

Abstract: In order to make a mask for use in lithography a layer of reflective material is first deposited on a substrate which is transparent to the radiation with which the mask is to be used; a layer of photoresist then deposited; the photoresist exposed with the desired pattern by UV radiation; the photoresist developed to expose the reflective material in the areas where it is desired to deposit an absorber material; the reflective material etched away from these areas undercutting the resist; the absorber deposited through the openings in the resist and reflective layer and the resist then lifted off.

Abstract: This invention provides, in a restricted off-axis field optical system having a broad spectral range, which includes refracting elements, the improvement comprising:an optical system constructed and arranged so that the Petzval sum is substantially zero, said refracting elements including elements for balancing the effects of the variation in the Petzval sum due to variation in color by introducing axial chromatic aberration of the opposite sense so that the position of focus at the off-axis field remains substantially constant;according to the invention in one form thereof, the elements for balancing the effects of the variation in the Petzval sum due to variation in color include a symmetrically disposed nearly concentric meniscus element whose convex radius is larger than its concave radius and whose thickness is greater than the difference between its convex and concave radii;further, according to a form of the invention, the system includes at least one convex and one concave mirror, said mirrors being n

Abstract: Anticipation signals are derived for each peak whenever a differential exists within a closed loop having the electrical output connected to the input thereof and a confirmation signal is derived after each peak at a threshold level of the new slope polarity exceeding the noise level of the electrical output. The amplitude of each peak is stored as a voltage level which follows the electrical output throughout either slope polarity until a peak is reached and this voltage level is continuously compared with the electrical output to derive the slope polarity thresholds. Otherwise, a very particular embodiment is disclosed with which the stored voltage level only relates to either the most significant maximum or minimum peak of the electrical output and the disclosed embodiments are related to instruments which perform spectral analysis.