Abstract: To determine the average velocity of a fluid stream, an ultrasonic signal is transmitted into the fluid and reflected ultrasonic signal received. The signals are mixed with a frequency of the transmitted ultrasonic signals. A Fourier transform is performed on the signals, the largest coefficient used to normalize the signal and certain of the weighted signals are averaged.

Abstract: In a piston pump for pumping liquid carbon dioxide at a temperature below 30 degrees Fahrenheit and pressures at least as high as 7500 psi, the volume leaving the pump is determined by measuring only pressure or other parameter related to flow and movement of the plunger. The position of the piston is measured and the resulting displacement is integrated to determine volume of fluid pumped.

Abstract: A variable-orifice fluid restrictor for use with a supercritical extractor or chromatograph includes an inlet line for fluid at a pressure above its critical pressure, an extended tubular probe having an inner and an outer surface and a proximal and a distal end. The proximal end of the probe is disposed toward the inlet line. The distal end of the probe includes an adjustable orifice means adapted for metering the fluid and having first and second orifice members and an adjusting stem having first and second ends. The adjustable orifice means is adjacent to the outer surface of the probe and the orifice means is adjustable with the adjusting stem. The end of the adjusting stem is located at the distal end of the probe and is adapted for moving the first orifice member with respect to the second orifice member to control the adjustable orifice for varying the restriction of fluid passing through the adjustable orifice.

Abstract: In a piston pump for pumping liquid carbon dioxide at a temperature below 30 degrees Fahrenheit and pressures at least as high as 7500 psi at an outlet flow rate in excess of 10 milliliters per minute, the inlet to the pump and the pumphead are each cooled by thermoelectric heat exchangers that are air cooled. The pump is a cam-driven, single-plunger pump with a cam profile that enables the pumping system to avoid distructive reverse torque on the cam, gear train and drive motor after the cam passes top dead center. The volume leaving the pump is determined by measuring only pressure or other parameter related to flow and movement of the plunger. The piston of the pump is supported on both sides of the seal and the support for the piston within the pumphead are machined consentrically and colinearly to the seal gland.

Abstract: To determine the total organic carbon content of a flowing liquid in a continuous process, water and oxidizing agents enter lower ports in a multi-stage column and flow upwardly through residence chambers as they are mixed. Spaced apart along the upper path of the liquid, there are helical reaction grooves relatively shallow and containing at least one helical groove to cause rapid motion of the liquid. An ultraviolet lamp extends downwardly through the center of the column so that the outer confining surface of the helical grooves is the outer surface of the ultraviolet lamp, causing the liquid to move rapidly in intimate contact with the ultraviolet lamp to receive intense radiation. The stages are separate and interchangeable so that selected sizes may interconnect. The residence chambers may have different sizes to permit different lengths of residence time and thus permit tailoring of the reaction to the expected organic carbon content and possible side reactions with other impurities in the water.

Abstract: To draw samples of fluid at remote locations, one of a plurality of sampler configurations is selected from configuations that have a universal base, a selected one of a composite container holder or locator, 12-container rain water runoff container holder and sequential sample multiple container holder; clampdown, control section and cover. The selected configuration is brought to the remote site. Samples are drawn at the site in a predetermined time sequence. After a sequence is completed, a new selected container carrier is put into an insulated shipping carton with ice and containers and brought to the site. At the site, the old container holder is removed and the ice is poured into the shipping carton. The new container carrier is inserted into the sampler and ice put in with it. The old container carrier with sample in the containers is put into the shipping carton with the remaining ice and brought to the laboratory.

Abstract: A method of making a sensor wherein flexible conduit means is assembled with a fixture having a strain-sensitive film and electrical connections are made to the film whereby variations in fluid pressure in the conduit means can be detected.

Abstract: To supply supercritical fluid to an automatic supercritical fluid extractor and collect extract from the extractor, sample holding cartridges are lifted one by one in series by an elevator plug into a pressure chamber. An inlet at the top of the cartridge engages a pressure vessel inlet for the extractant so that extractant flows into the cartridge and into the space between the cartridge and inner walls of the pressure chamber. The outlets from the cartridge and pressure vessel communicate with the collector and exhaust through passageways in the plug. The plug has cleaning ports for cleaning seals and the outlet from the cartridge flows past the seals. The collector lifts vials into place and can precool the collection solvent, and later as part of the collection procedure, heat and pressurize the collector.

Abstract: To detect bands in an electrophoresis capillary tube having a liquid separating medium, a light source and a light detector of a monitor are positioned on opposite sides of the capillary tube with the light source transmitting light through a first slit and light passing to the detector through a second slit after it has passed through the capillary tube. The first and second slits are aligned with the direction of motion of bands, have a maximum length of less than 500 micrometers and a maximum width of less than 200 micrometers. There are no vertical lengths in the capillary tube having a dimension greater than one third of its length between a sample injecting end and a detecting end of the capillary tube.

Abstract: A preparatory supercritical extraction cartridge includes a chamber for sample having a volume in the range of 20 cubic centimeters to 2,000 cubic centimeters. An inlet and an outlet are fastened to the cartridge walls by threads and sealed to said cartridge walls With spring loaded seals so that they can be removed with a torque requirement of less than 35 pound inches. Inlet and outlet tubing are fastened to the inlet and outlet by quick release connectors.

Abstract: To avoid deposits on the restrictor that channels extractant into a collector, a heated capillary tube pressure release restrictor, has a thermally insulated outlet end in a collecting trap substantially colder than the capillary tube. The restrictor is heated between the insulation and the capillary tube by Joulean heating. The solvent in the trap is at a pressure of 5 to 200 psi above atmospheric pressure. The thermal resistance of the insulation is selected to reduce the heat added to the extractant to a minimum and yet cause the temperature of the extractant to be in a range within which it is sufficiently hot so it does not freeze when added to the collection solvent but not so hot as to reduce partitioning of the extract and extractant before the extractant leaves the collection solvent. It has a thermal conductivity no greater than 60 BTU's per hour, per square foot, per inch for a one degree Fahrenheit difference.

Abstract: A composite wastewater sampler includes a flow-through-chamber having an inlet port and an outlet port with a path between them that gradually increases in depth and width and then decreases in width. It is shaped to cause fluid to: (1) flow from the inlet port; (2) drop to a lower level of flow within the flow-through-chamber; (3) gradually adjust in cross-sectional shape to the outlet port; and (4) flow back into a wastewater pipe. A sampling nozzle extends into the flow-through-chamber adjacent to the inlet port and within the path of the downwardly flowing wastewater so that wastewater exiting the port contacts the nozzle and flows downwardly across it.

Abstract: To pump supercritical carbon dioxide into a supercritical extractor without overpressure in the reservoir and to record the volume being delivered, the pumping speed is controlled and the volume pumped is determined from a pressure-related signal used in a feedback circuit. The feedback controls the velocity of pumping in conjunction with programmed values to avoid destructive reverse torque. A cam in the pump controls piston stroke, has a depressurization portion with an initial slope equal to but in the opposite direction of the final slope, rounded transition slopes, increasing linear velocity to the refill portion and constant velocity in the refill portion.

Abstract: To detect bands in an electrophoresis capillary tube having a liquid separating medium, a light source and a light detector of a monitor are positioned on opposite sides of the capillary tube with the light source transmitting light through a first slit and light passing to the detector through a second slit after it has passed through the capillary tube. The first and second slits are aligned with the direction of motion of bands, have a maximum length of less than 500 micrometers and a maximum width of less than 200 micrometers. There are no vertical lengths in the capillary tube having a dimension greater than one third of its length between a sample injecting end and a detecting end of the capillary tube.

Abstract: A variable-orifice fluid restrictor for use with a supercritical extractor or chromatograph includes an inlet line for fluid at a pressure above its critical pressure, an extended tubular probe having an inner and an outer surface and a proximal and a distal end. The proximal end of the probe is disposed toward the inlet line. The distal end of the probe includes an adjustable orifice means adapted for metering the fluid and having first and second orifice members and an adjusting stem having first and second ends. The adjustable orifice means is adjacent to the outer surface of the probe and the orifice means is adjustable with the adjusting stem. The end of the adjusting stem is located at the distal end of the probe and is adapted for moving the first orifice member with respect to the second orifice member to control the adjustable orifice for varying the restriction of fluid passing through the adjustable orifice.

Abstract: An apparatus for supercritical fluid extraction incorporates a removable extraction cartridge which in operation has insignificant pressure difference between its inside and outside walls. Because of the low pressure difference, the extraction cartridge need not have the strength to withstand significant pressure and can be made out of molded plastic for disposable use as well as stainless steel and/or machined plastic for reusability. The extraction cartridge can be removed and opened for sample access without the use of tools. The outside of the cartridge can be purged after it is installed in a heated high pressure vessel to remove contamination from its exterior. In one embodiment, the extractor includes a fraction collector for extractants, an automatic sample changer and an automatic cartridge transfer mechanism which provide completely automated extractions.

Abstract: To collect analyte in a supercritical fluid extraction process, the extractant flows to a collection container under pressure. In one embodiment, the collection container contains collection solvent through which the extractant flows to partition analyte. The extractant adds to the liquid and when the collection solvent-extractant mixture rises to a heating zone, the extractant vaporizes selecively since its vapor pressure is higher than the vapor pressure of the collection solvent. When its pressure exceeds a preset valve pressure it is vented so that extractant continually leaves the collection container. After the extraction is complete, the analyte is concentrated in the collection solvent. In another embodiment, the collection vessel includes a solid material on which the analyte collects. It is removed under pressure by a solvent that is concentrated under pressure.

Abstract: To select a designated bottle in a sampler, the distributor is calibrated as to position and the outlet of the distributor arm is moved over the desired bottle by counting changes in incremental angular movement of the distributor arm until it is over the bottle. The position of the distributor arm is recorded in memory. To calibrate the distributor, the arm is rotated against a stop member in a first direction, then in a second direction and the overrun of in excess of 360 degrees of the motion of the distributor arm is determined and corrected. A series of random numbers is generated for depositing of samples, the distributor is moved at designated times over the bottles in a random order to deposit a sample and the ordering of bottles is recorded. The rollers of a peristaltic pump are supported to prevent said rollers from compressing said tube more than the thickness of the walls of the tube. A functional module for a bubbler or pH probe or ultrasonic level detector may be connected to the housing.

Abstract: To determine the average velocity of a fluid stream, an ultrasonic signal is transmitted into the fluid and reflected ultrasonic signal received. The signals are mixed with a frequency of the transmitted ultrasonic signals. A Fourier transform is performed on the signals, the largest coefficient used to normalize the signal and certain of the weighted signals are averaged.