Abstract: The invention includes a toploading weighing instrumentality which determines loss on drying by a cylindrical microwave. The cylindrical cavity of the microwave includes a power supply, a magnetron, a power module operatively coupled between the power supply and the magnetron for driving the magnetron, a wave guide communicating with the magnetron and with a microwave containment chamber for delivering energy, and at least one microwave energy sensor for sensing microwave energy or magnetic and/or electric field strengths within the chamber for controlling, inter alia, the loss on drying process of the sample being assayed and determining when the drying process is complete. A precision electronic balance is operatively disposed within the microwave chamber for allowing a specimen being assayed to be weighed. In addition, a ventilation chamber is provided for venting moisture from the microwave chamber. A processing unit provides for data acquisition, processing and storage.
Type:
Grant
Filed:
June 5, 2001
Date of Patent:
December 12, 2006
Assignee:
Denver Instrument Company
Inventors:
Robert F. Scalese, Thomas B. Taylor, Tim Holzschuh, Douglas E. Harbert, Thomas G. Plaven, Martin L. Maple, Jan Claesson
Abstract: A toploading weighing instrumentality which determines loss on drying by a cylindrical microwave. The cylindrical cavity of the microwave includes a power supply, a magnetron, a power module operatively coupled between said power supply and said magnetron for driving said magnetron, a wave guide communicating with the magnetron and with a microwave containment chamber for delivering energy thereto, at least one microwave energy sensor for sensing microwave energy or magnetic and/or electric field strength within the chamber for controlling, inter alia, the loss on drying process of the sample being assayed and determining when the drying process is complete. A precision electronic balance is operatively disposed within the microwave chamber for allowing a specimen being assayed to be weighed. In addition, a ventilation chamber is provided for venting moisture from the microwave chamber.
Type:
Grant
Filed:
May 27, 1998
Date of Patent:
June 19, 2001
Assignee:
Denver Instrument Company
Inventors:
Robert F. Scalese, Thomas B. Taylor, Tim Holzschuh, Douglas E. Harbert, Thomas G. Playen, Martin L. Maple, Jan Claesson
Abstract: A toploading weighing apparatus which determines weight loss for a sample by drying the sample in a cylindrical microwave with a specific structure.
Type:
Grant
Filed:
February 10, 1998
Date of Patent:
July 25, 2000
Assignee:
Denver Instrument Company
Inventors:
Robert F. Scalese, Thomas B. Taylor, Tim Holzschuh, Douglas E. Harbert, Thomas G. Plaven, Martin L. Maple, Jan Claesson
Abstract: A rotor assembly for use in a centrifuge is provided including a rotor body having a plurality of apertures for holding fluid containers. An impervious cover fits tightly on the rotor body to provide a seal for the rotor to prevent the escape of any sample from the rotor. Further, a mechanical connection system permits the rotor to be connected to and disconnected from a drive motor while the cover is sealing the rotor.
Abstract: A weight switching mechanism for a substitution type analytical balance is provided which permits the automatic selection and lifting of the required substitution weights from the gimbal assembly of a balance beam to allow accurate weighing of an unknown mass. A capacitive/electromagnetic feedback device is provided for sensing changes in the relative balance of the beam with respect to the applied unknown mass. The resultant current is applied to a force coil which maintains the beam in null position. A current related signal is converted to a digital input signal which is applied to a memory and control circuit and electronically displayed. A series of electromagnets, mounted below a printed circuit board and positioned to correspond with each substitution weight, is provided. The printed circuit board is arranged to lift upon release of the balance beam.