Abstract: A temperature control apparatus for a high temperature reactor in an analytical instrument of the type in which a development reagent is added to a flowing stream as part of the detection process. The temperature control apparatus utilizes solid state heat transfer means to transfer heat between a thermoconductive block to which is mounted the reactor and an air exchange heat sink which obtains heat from or disposes heat into ambient air as required. The control apparatus regulates the temperature of the reactor at a very rapid rate in the high temperature range of approximately 90.degree. C. to 150.degree. C. without the use of a separately contained heat exchange medium. The ability of the apparatus to cool the reactor rapidly eliminates the requirement to keep reactor contents at elevated pressures to prevent vaporization of the stream being analyzed.

Abstract: A method for driving a stepper motor. The method includes varying the width of the high level drive impulses of a bi-level drive system based on the desired speed to be achieved by the stepper motor. A microprocessor is used to vary the pulse width.

Abstract: A column for use in DNA synthesis. The column is transparent and is disposable to allow access to the resin beads within the column. The column includes end caps which are engageable with a housing and a screw to secure the column in the housing.

Abstract: A liquid transfer valve including a movable valve portion. A second valve portion is movable with respect to a first valve portion to allow probes to extend therethrough to pick up a liquids. Upon probe retraction, the second valve portion is movable to a position which allows the liquids to be injected into the valve where they are diluted, mixed, and carried to a remote detector or delivery point.

Abstract: An elongate straight column for use as a reactor in an analytical instrument. The column contains inert packed material which provides for the necessary flow path length for a fluid stream entering the reactor. Fittings are incorporated onto the ends of the column in such a manner that their width is no larger than the width of the column. The column configuration for a reactor allows more versatility in the type of temperature regulator mechanisms used to heat and cool the reactor.

Abstract: A method and apparatus for determining an insufficient liquid volume. The invention includes an electromagnetic sensing device in a conduit into which the sample liquid is mixed. The electromagnetic sensing device detects the presence of air in the conduit which indicates that an insufficient liquid volume has been aspirated.

Abstract: A method and apparatus for monitoring flow rate through a conduit. A flow number indicative of the flow rate of a liquid through the conduit is compared with a preselected reference number. The actual liquid flow through the conduit provides a clocking signal which determines the time span during which a count signal, indicative of the intended flow rate into the conduit, is accumulated thereby providing the flow number.

Abstract: An electrophoretic gel container. The device includes a base and a cover. The gel is adherently bound to a backing sheet. The cover is positioned to clamp the backing sheet between it and the base. The cover is spaced from the gel.

Abstract: A temperature regulating apparatus which increases optical sensitivity and resolution of a liquid in a reaction chamber by heating while providing rapid cooling to prevent vaporization of the liquid within the reaction chamber. The apparatus includes a heat exchanger containing the reaction chamber and an insulating chamber surrounding the heat exchanger. A coolant may be passed through the heat exchanger to prevent boiling should a change in liquid flow make such occurrence likely. The change in liquid flow is monitored by an analyzer monitor, and the temperature in the reaction chamber is changed accordingly.

Abstract: A thermodilution catheter having a distal high frequency heating coil of fine wires, heat measuring thermocouples, and a proximal resistance thermometer, all wound externally on a catheter for measuring blood flow in either the jugular vein or the left ventricle of the heart. The device also incorporates electrodes for electrocardiogram tracings.

Abstract: A self-contained, portable, underwater stud welder includes a hand-held welding gun and a battery powered backpack. The welder uses a bank of rechargeable nickel-cadmium batteries which charges a storage inductor, the energy of the inductor being transferred to a bank of capacitors, providing a high efficiency method of charging the capacitor bank so the battery bank is kept small.

Abstract: A shuttering servo system which is phase synchronized to the vertical rete time of a television camera. Circuitry is provided to lock the leading edge of the signal from a photo detector on a disc shutter motor shaft to the leading edge of the camera's vertical drive output. A form of tachometer feedback is used to stabilize the circuit.