Abstract: An improved multi-channel galvanometer assembly is disclosed particularly well adapted for use in such instruments as electroencephalographs and the like. The assembly includes a soft steel combination return path structure and frame supporting a plurality of galvanometer movements. The design employs pairs of samarium cobalt magnets held in place adjacent and on opposite sides of the coil of each galvanometer by magnetic attraction to the steel return path structure. The galvanometers themselves are each mounted on an aluminum support plate which also serves as a shield to prevent magnetic coupling between adjacent galvanometer coils when the galvanometers are assembled in the support frame. The galvanometers on their support plates are each individually removable and/or replaceable. The result is a lighter, smaller, multi-channel galvanometer assembly which is readily expandable and easily serviced.

Abstract: A fluid dispenser including a syringe having a reciprocating syringe plunger for controlling syringe fluid intake and discharge and a traveling slide connected to the plunger for driving the plunger. The traveling slide is bearing mounted in sliding relationship on a fixed shaft and is driven therealong by a pinion gear engaging a rack secured to the slide.

Abstract: A device for use with variable electrical components such as potentiometers to provide not only an independent means adjacent the control knob to lock the knob in a fixed position, but also to provide variable amounts of drag on the knob to enhance more precise and accurate control of the knob. The locking device is positioned between the controlled component and the control knob. The locking device can be moved to a plurality of positions adjacent the control knob to vary the amount of drag on the control knob.

Abstract: An automatic spectrum scanning technique for use in a proportional counting instrument, such as a gamma counter or liquid scintillation counter, by means of which a pulse-height or energy spectrum of a sample can be obtained automatically and without multichannel instrumentation. A pulse-height analyzer in the counting instrument has its upper and lower discriminator limits set to define a relatively narrow counting window, and the limits are successively changed to scan the window across the energy spectrum and thereby obtain an accurate measurement thereof. Counting at each increment of the scan is continued for a preselected maximum time interval, but is quickly terminated if the count rate falls below a preselected low threshold value, and is terminated early if the count rate is relatively high, i.e., if the statistical error value associated with the count is relatively low.

Abstract: Apparatus for measuring CO.sub.2 in serum with a single pH sensor of the electrolyte flow-through type, the sensor including a gas-permeable membrane selectively passing CO.sub.2 into an electrolyte filled space adjacent a pH sensing electrode for reacting with the electrolyte to produce a pH change therein. The electrolyte space is connected by a conduit to an electrolyte reservoir for flowing fresh electrolyte to and through the electrolyte space prior to a sample measurement. A stainless steel metal electrode directly contacts the electrolyte of constant composition in the conduit upstream of the pH sensor to derive a reference potential thereat. The potential across the pH sensor and the stainless steel electrode is monitored, differentiated, and the maximum value of the differentiated signal measured to determine the CO.sub.2 concentration.

Abstract: Powder compositions useful for making conductors, e.g. microcircuit conductors, end terminations for capacitors, electrodes for gas discharge display devices, etc. The compositions comprise inorganic powders dispersed in an inert vehicle and are printed and fired in the conventional manner on dielectric substrates. The inorganic powders comprise aluminum, silicon, and glass.

Abstract: An insert for use with swinging bucket rotors at the interface between the swinging bucket and the rotor arm trunnions which pivotally support the bucket. The insert is designed to decrease the friction between the swinging bucket and the support trunnions.

Abstract: In apparatus for analyzing the exhaust gas of a motor vehicle, the apparatus including an oxygen sensor and means for sampling a portion of the exhaust gas and conducting the sample to the sensor, there is disclosed an improvement wherein the exhaust gas is used to heat a moisture barrier and the oxygen sensor and is then cooled before being directed through the moisture barrier to the sensitive area of the oxygen sensor. This arrangement prevents moisture from condensing on the sensitive area of the oxygen sensor, which moisture would interfere with the operation of the sensor.

Abstract: Nematic liquid crystal compositions containing 4'-substituted-4-cyanobiphenyl and 4, 4'-disubstituted phenyl benzoate liquid crystal compositions which can be actuated at low voltages, e.g., under 3.5 Vrms in a 12.5 micron thick twisted nematic liquid crystal display.

Abstract: A carrier assembly for pivotal placement on a swinging carrier rotor wherein the carrier has a support member which maintains the carrier assembly in a centered location between the hinge pins on the rotor. The carrier assembly has a frame unit which holds a microtitration plate containing samples to be centrifugated. The support member in the carrier assembly is slidably engaged with the frame unit and eliminates the need for welds. Each end of the support member has a generally semicircular sleeve portion which provides for the easy placement and removal of the carrier assembly from the rotor hinge pins. Retaining means are positioned on the support member to prevent deflection of the carrier frame unit along the support member during centrifugation.

Abstract: In a multilayer gas-discharge display panel of the type including a plurality of character blocks, each including a plasma supply reservoir section, a control anode section, and a display section, such sections being arranged in a plurality of parallel, gas-filled columns defining a display matrix, the supply reservoir providing a source of ions which are selectively conducted by the control anodes to the display section, a voltage being applied to the display section to initiate a gas breakdown in those columns which have had ions conducted therethrough by the control anodes, an improved display section is disclosed comprising a transparent, insulating plate extending across the front of the panel, perpendicular to and covering all of the columns, a transparent electrode covering the front surface of the plate, on the opposite side of the plate from the supply reservoir and the control anodes, and means for applying voltage pulses of alternating polarity to the electrodes to create a flashing discharge in ea

Abstract: A brake circuit for a universal motor having an armature and a field winding normally connected in series therewith, the circuit including switch means operable to disconnect the power source and electrically connect the armature in series with the field winding and a brake resistor, with voltage limiting means in parallel with the field winding. The voltage limiting means include biasing diodes for maintaining the voltage across the field generally constant, resulting in a more even deceleration rate and a lower total brake time.

Abstract: A centrifuge rotor assembly having a resilient liner with at least two separate chambers. Fluid communication between the separate chambers is automatically controlled in response to centrifugation operation of the rotor. When the rotor is stationary, the liner assumes a first position within the rotor where an annular chamber is sealed from a central chamber. When a fluid sample is placed within the liner of the rotor and the rotor is subjected to centrifugation, the centrifugally induced forces of the fluid mixture shift the liner to a second position, opening the sealed condition between the central and annular chambers to permit fluid communication between the respective chambers. When the centrifugation operation has been completed and the rotor returns to its stationary position, the inherent resilient structural characteristics of the liner automatically re-establish the seal between the respective chambers.

Abstract: A rotor having a plurality of swinging carriers designed to receive specimen samples for subjection to centrifugation. The carriers are pivotally mounted to a rotor frame in such a manner that the generally flat support faces of each of the carriers assumes a parallel orientation with respect to the rotational axis of the rotor during operational speeds of the rotor. When the rotor is not operating, the support surfaces of each of the carriers assumes the perpendicular or acute angle orientation with respect to the rotational axis of the rotor. In order to overcome any resistive frictional forces which may be generated at the interface between the rotor frame and the pivoting carrier, the pivot axis of the carrier is shifted from the central or center of gravity plane of the carrier to ensure that the support surface of the carrier will positively assume its proper parallel orientation with the rotor spin axis.

Abstract: A nephelometer including an optical excitation system for directing light through a first window area into a cylindrical glass container and an optical detection system for quantitatively monitoring light scattered by a substance within the container and passing therefrom through a second window area. The optical detection system includes a lens system in optical alignment with the second window area and focused on an optical dark region on an inner wall of the container opposite the second window area. The optical dark region is free of internal light reflections. Therefore, the light monitored by the detection system is scattered light from the substance substantially free of internal light reflections representing background error.

Abstract: A pivotal carrier for use in centrifuge rotors wherein the ends of the rotor carriers are adjustable to vary the supporting or receiving surface area in the carrier to accommodate various sized tube racks which may be used in the centrifuge rotor. Holding members in opposite ends of each carrier are movable to a plurality of positions to symmetrically position the tube rack within the carrier to maintain dynamic rotor balance.

Abstract: A hermetic glass seal to provide the final seal for the fill ports in the glass walls of a display device such as a liquid crystal display. The seal utilizes a glass bead sandwiched between a metal cover and a polymeric separator.

Abstract: A gas discharge display device for exhibiting an analog value in a sealed envelope having a viewing window with a plurality of linear cathode segments arranged in succession to form a row or column capable of exhibiting a glow discharge. The cathodes are arranged in groups within the sealed envelope with a separate anode electrode in operative relationship with each of the groups of cathodes. Alternate ones of the anode electrodes are activated simultaneously in alternating sequence, so that the time duration of cathode glow exhibited on each cathode segment is increased to provide a significant increase in the intensity of the bar graph display. The intensity of the bar graph may be decreased to accommodate a surrounding environment by reducing the on time for each cathode segment.

Abstract: A process for making an integral one piece rotor liner for use with a high speed rotor. The liner has an inner chamber and an annular chamber designed to operate in conjunction with the rotor operation to automatically allow fluid communication between the respective chambers during centrifugation and automatically establish a seal between the respective chambers subsequent to the centrifugation operation. The process for making the one piece rotor liner generally comprises a first step of molding the liner in an intermediate elongated configuration wherein the inner chamber portion is integrally joined to and spaced from the annular chamber portion of the liner by a reversing section. The general configuration of the inner chamber is located at one end of the elongated liner shape and the general configuration of the annular chamber is located at the other end of the elongated liner.

Abstract: The range of linearity of the kinetic method for the determination of glucose concentrations using a reagent of the type comprising a buffer, a pyridine coenzyme, and glucose dehydrogenase, is significantly increased when the buffer employed in the reagent has a pH of from about 7.9 to about 9.0.