Micromeritics Instrument Corporation

Georgia Tech Research Corporation

Micromeritics

Micromeritics Instrument Co.

Clyde Orr, Jr

Ronnie W Camp

Dean M Ball

Warren P Hendrix

James P Olivier

Jack J Wagner

Graham R Killip

Samuel V Tidwell

Kathryn H Gibson

Mary F Kane

Robert C Fincher

Charles L Laughinghouse

A compaction device for determining envelope and bulk densities of sample materials. The device uses a rotating sample cylinder and a plunger positioned within the cylinder. The force on the plunger is measured as the plunger advances in the cylinder. The position of the plunger at which a predetermined level of force is applied thereto is determined. Envelope density is determined from the difference in the advance of the plunger when the cylinder is partially filled with a dry flowing medium and when a sample material such as a rigid object is added into the medium. Bulk density is determined from the difference in the advance of the plunger when the cylinder is empty and when the cylinder contains a sample material such as a powder.

Method and apparatus for measuring envelope and bulk densities

An apparatus and method for measuring the volume and calculating the envelope density of an object of known weight. The apparatus has a hollow sample cylinder of known interior diameter mounted to a motor for rotation about its horizontal axis. A dry flowing medium is placed in the sample cylinder and a plunger is removably positioned therein. The plunger is mounted to another drive motor for axial movement within the sample cylinder to compact the dry flowing medium. A load cell connected to the plunger measures the force on the plunger as it advances in the sample cylinder. Control means responsive to the load cell determines the position of the plunger in the sample cylinder at which a known force is exerted on the plunger. The control means also calculates the volume of the dry flowing medium in the sample cylinder both with and without the object positioned therein and divides the difference in the volumes into the weight of the object.

Method and apparatus for measuring envelope density

An x-ray sedimentation particle size analyzer in which data is taken only at particular positions along the sedimentation cell, and each such position is individually calibrated. Presentation of the data in the form of a particle size distribution curve can be accomplished very accurately using interpolation techniques. The sedimentation cell design is free of the effects of undesirable density gradients, capable of detecting and removing bubbles, capable of attaining a highly uniform dispersion of sample prior to sedimentation, and including a safety interlock device for blocking x-ray projection when the cell is being accessed.

X-ray particle size analyzer

A gas comparison pycnometer is disclosed which provides a method and apparatus for determining and checking the accuracy of the volume of a solid substance. The pycnometer is also outfitted with a unique cap assembly which fixes the volume in the pycnometer's sample chamber from run to run. The pycnometer also employs a series of purges with a suitable gas to carry unwanted moisture and vapors out of the system. This pycnometer solves many problems in the prior art by quickly and accurately determining the volume of a solid substance.

Gas comparison pycnometer

An automatic sample feeder system for handling suspended samples is disclosed, and is particularly useful in connection with a sedimentation particle size analyzer. The system is capable of dispersing a particulate sample into suspension without preliminary sample preparation, maintaining a sample in suspension at the time of delivery of the sample to an analyzer, consistently delivering an acceptable concentration of a suspended sample, and cleaning and flushing its components between samples to avoid contamination. In the disclosed embodiment, sample beakers are arrayed on a rotatable tray, and a sample preparation and delivery assembly consisting of an ultrasonic probe, a stirrer blade, and a dip tube are indexed into position over the beakers in a preprogrammed sequence, and lowered into the beaker for preparation and withdrawal of the sample. The components are rinsed by directing clear liquid back through the dip tube onto the rotating stirrer blade, scattering the liquid.

Automatic sample feeder for suspended samples

An apparatus for maintaining a constant temperature within a vessel immersed in a liquid by surrounding a portion of the vessel, extending above the surface of the liquid, with a wick. The wick conducts liquid up to a predetermined point on the vessel and maintains the liquid at that point, regardless of changes in the level of the liquid due to evaporation. The wick is encased within a layer of heat insulating or heat conducting material to further aid in maintaining a constant temperature within the vessel. A second embodiment, including alternating layers of heat conducting and heat insulating material, is disclosed for increased temperature control. The disclosed apparatus is particularly useful for maintaining a constant temperature within a vessel attached to a scientific instrument, such as a pore volume and surface area analyzer.

Temperature controlling apparatus for use with pore volume and surface

A fractionating apparatus under microprocessor control including a tumbler having a series of screens of progressively larger openings around its periphery. A sample of particulate material is passed successively through each of the screens by incremental rotation of the tumbler. To aid in classifying the fractions, a spray of fluid is projected against the screens and a rocking motion is imparted to the tumbler. The smallest fraction, not being retained, is entrained in a moving stream of fluid and passed directly to a porous weighing member. When this entire fraction is deposited and weighed, the next larger fraction is accumulated in the weighing member. These individual weights and their sum are recorded and from them size percentages are computed.

Method and apparatus for automatically fractionating a sample of

Particles suspended in a fluid medium are separated into isolated fractions by size by passing a suspension of such particles through an unobstructed passageway, the particles emerging from the passageway in decreasing order of size.

Particle size separation by suspension flow in an unobstructed passageway

Sample introduction apparatus useful in liquid chromatography and including a valve body having at least one fluid passage of precisely defined volume to receive a sample material and having another fluid passage delivering carrier liquid to a liquid chromatograph. The valve body can be manipulated to place the precisely defined volume in the chromatograph fluid circuit, so that the sample contained within the volume is positively displaced into the chromatograph.

Liquid chromatography sample measuring and introducing apparatus

A sample of particulate material is entrained in a moving body of fluid and the fluid is continuously discharged through a porous weighing member. Before passing to the weighing member sized fractions within the sample, except for the smallest one, are separated and held back at different regions in the body of fluid so that only the one fraction initially deposits on the weighing member. The weight addition of this fraction is measured and then a further fraction is re-entrained to move with the fluid to pass to and deposit on the weighing member cumulatively with the first fraction. The weight increase caused by this further deposition is measured and the re-entrainment and weight increase measurement of still further fractions are effected separately and successively until all fractions are deposited on the weighing member. These individual weights and their sum are recorded either manually or automatically and from them size percentages are computed. Further samples may be similarly processed while the weighing member accumulates all samples until its capacity is reached, whereafter the weighing member must be cleaned or replaced. The several size fractions may be separately recovered when a multiplicity of weighing members is employed.

Method and apparatus for determining the relative weight proportions of

Apparatus used in the field of liquid chromatography. There is disclosed pump apparatus for continuously delivering a flow of carrier liquid either at a constant rate of flow or at a constant pressure. The pump apparatus includes a pair of differential-piston pressure intensifiers which are sequentially operated so that the high-pressure sides of the pressure intensifiers sequentially supply carrier liquid to the chromatograph column. Each pressure intensifier is sequentially operated by a constant-rate of flow application of hydraulic liquid, with essentially pulseless operating transition between pressure intensifiers occurring during constant-pressure application of hydraulic liquid to both of the pressure intensifiers at a pressure measured during previous constant-volume hydraulic operation. An embodiment of the pump apparatus pumps plural carrier liquids in desired fixed or variable proportions. There is also disclosed sample introduction apparatus including a valve body having at least one fluid passage of precisely defined volume to receive a sample material and having another fluid passage delivering carrier liquid to a liquid chromatograph. The valve body can be manipulated to place the precisely defined volume in the chromatograph fluid circuit, so that the sample contained within the volume is positively displaced into the chromatograph. Chromatograph recycling apparatus is also disclosed which permits a selected sample portion to be retained after passing through a chromatograph column, and to be subsequently re-introduced into the column for further analysis. Apparatus is also disclosed for intermixing plural liquids flowing in a conduit. Improved detector apparatus for use with a chromatograph is also disclosed.

Growing community of inventors

Dunwoody, GA, United States of America

Clyde Orr, Jr