Abstract: A flow conditioning system includes a flow randomizing section for receiving an input fluid stream and for increasing the uniformity of the streamwise velocity components of the input fluid stream while randomizing the non-streamwise velocity components, so as to provide a randomized fluid stream; a flow expansion section for receiving the randomized fluid stream and damping the non-streamwise velocity components therein, so as to provide a damped fluid stream; and a flow straightening section for receiving the damped fluid stream and for dividing the damped fluid stream into multiple, parallel output substreams so as to provide a laminar flow profile in an output fluid stream.

Abstract: A simplified method and apparatus for electronic pressure control with compensation for current operating temperature and pressures in which computer memory is employed for storing a plurality of firmware models which characterize the effects of temperature and pressure variations on (1) fluid flow through the flow restrictor, (2) the temperature sensor, and (3) the pressure sensor, so that control signals can be generated which compensate a plurality of thermally coupled sensors for changes in current operating temperatures and pressures.

Abstract: A chromatograph includes an injector for receiving a sample and a pressurized carrier fluid flow and in response providing a sample/fluid mixture; a separation column located in a temperature-controlled zone for receiving the sample/fluid mixture and for providing a column effluent stream; a pneumatic detector having an orifice for receiving the effluent stream; means for sensing the volumetric flow rate of the fluid mixture entering the column and for generating a respective flow rate signal; means for sensing the column input pressure and generating a respective input pressure signal; an electronic pneumatic controller including means for receiving the flow rate signal and input pressure signal and for controlling in response the input pressure and the volumetric flow rate of the carrier fluid; and means for detecting a change in the pressure of the effluent stream at the orifice in response to a change in the density of the effluent stream passing through the orifice and for generating a representative out

Abstract: A flow conditioning system includes a flow randomizing section for receiving an input fluid stream and for increasing the uniformity of the streamwise velocity components of the input fluid stream while randomizing the non-streamwise velocity components, so as to provide a randomized fluid stream; a flow expansion section for receiving the randomized fluid stream and damping the non-streamwise velocity components therein, so as to provide a damped fluid stream; and a flow straightening section for receiving the damped fluid stream and for dividing the damped fluid stream into multiple, parallel output substreams so as to provide a laminar flow profile in an output fluid stream.

Abstract: Sample analysis in a portable analytical instrument, preferably in the form of a gas chromatograph, benefits from temperature control of one or more thermal zones in the instrument by way of a thermal isolation system that includes a novel pumping assembly to effect a selective amount of thermal isolation of the thermal zone. The pumping assembly includes a pumping element in the form of a tubular or planar palladium structure. The pumping assembly makes use of the unique properties of palladium to allow selective control of a nominal gas pressure within a vacuum cavity. A component system, which may include a separation column and a thermal device for heating and/or cooling the component system, may be provided within the vacuum cavity. The thermal device and the pumping assembly are individually controlled by a control system.

Abstract: Sample analysis in a portable analytical instrument, preferably in the form of a gas chromatograph, benefits from temperature control of one or more thermal zones in the instrument by way of a thermal isolation system that includes a novel pumping assembly to effect a selective amount of thermal isolation of the thermal zone. The pumping assembly includes a pumping element in the form of a tubular or planar palladium structure. The pumping assembly makes use of the unique properties of palladium to allow selective control of a nominal gas pressure within a vacuum cavity. A component system, which may include a separation column and a thermal device for heating and/or cooling the component system, may be provided within the vacuum cavity. The thermal device and the pumping assembly are individually controlled by a control system.

Abstract: A simplified method and apparatus for electronic pressure control with compensation for current operating temperature and pressures in which computer memory is employed for storing a plurality of firmware models which characterize the effects of temperature and pressure variations on (1) fluid flow through the flow restrictor, (2) the temperature sensor, and (3) the pressure sensor, so that control signals can be generated which compensate a plurality of thermally coupled sensors for changes in current operating temperatures and pressures.