Differential Thermal Analysis Patents (Class 374/10)
  • Patent number: 4925314
    Abstract: A device for detecting and/or measuring a thermal phenomena occurring in a product showing a liquid state at a temperature within the range of temperatures swept by the detecting and/or measuring device. An enclosure is provided with a calorimetric head containing at least one measurement cell which is adapted to be filled and emptied. Heat is transferred to the cell and a magnitude relating to a temperature of the cell is measured so as to obtain desired information regarding the product.
    Type: Grant
    Filed: December 19, 1988
    Date of Patent: May 15, 1990
    Assignee: Institut Francais du Petrole
    Inventors: Pierre Claudy, Jean-Marie Letoffe, Jean-Claude Commercon
  • Patent number: 4901061
    Abstract: Instrumentation and monitoring systems utilize, as differential temperature sensors, heated, split-well thermowells of duplex design, mounted to the sidewall of a pressure vessel and communicating through a penetration in the sidewall with the fluid state within the vessel. Each probe has at least one parallel axial bore therein, a related, selected pair of probes receiving respective heater and temperature sensing elements in the associated bores and together functioning as a differential temperature sensor producing distinguishable, differential temperature outputs representative of the presence of steam versus water. The systems monitor the differential temperature outputs of plural such sensors to produce alarm indications and perform verification and error checking of the sensor output indications.
    Type: Grant
    Filed: May 20, 1988
    Date of Patent: February 13, 1990
    Assignee: Westinghouse Electric Corp.
    Inventor: Michael Twerdochlib
  • Patent number: 4874250
    Abstract: The automatic serial testing of the heats of transformation of material samples is accomplished. The samples are enclosed in capsules which are placed into sample carriers on a turntable. A transfer mechanism transfers the capsules from the turntable to a controllably heatable test sample receiver and, after the measurement, back to the turntable. The entire arrangement is located in a housing filled with nitrogen. The sample carriers with the capsules can be inserted into this housing and onto the turntable through an air lock.
    Type: Grant
    Filed: December 4, 1986
    Date of Patent: October 17, 1989
    Assignee: The Perkin-Elmer Corporation
    Inventor: Winfried Gonner
  • Patent number: 4859076
    Abstract: A heated, split thermowell comprises a cylindrical shank and integral, axially extending, part-cylindrical probes spaced by at least a first gap defined by a bilateral plane. The thermowell is mounted to the sidewall of a pressure vessel for communicating through a penetration in the sidewall with the fluid state in the pressure vessel. Each probe has at least one parallel axial bore therein, a related, selected pair of probes receiving respective heater and temperature sensing elements in the associated bores, and together functioning as a differential temperature sensor producing distinguishable, differential temperature outputs representative of the fluid condition of steam versus water. Duplex sensor embodiments permit toggling between different, selected such pairs of probes for on-line testing and verification of monitored conditions and operability of the elements and supporting circuits, with automatic substitution of complementary elements in the event of element failure.
    Type: Grant
    Filed: May 20, 1988
    Date of Patent: August 22, 1989
    Assignee: Westinghouse Electric Corp.
    Inventor: Michael Twerdochlib
  • Patent number: 4812051
    Abstract: A temperature controlling system for investigating thermal transformation having a program-controller operated furnace the temperature of which is changed with a predetermined speed, and into which a sample and a reference substance containing elements with identical thermal parameters are placed. The sample and the reference substance containing elements are coupled with temperature sensing elements detecting their temperature and both elements are connected to a temperature comparing unit forming the difference of the two temperatures. The output of the temperature comparing unit is coupled through a differentiating network, limit switches and an actuating unit with a quasi-static temperature input of the program controller.
    Type: Grant
    Filed: April 30, 1986
    Date of Patent: March 14, 1989
    Assignee: Magyar Optikai Muvek
    Inventors: Jeno Paulik, Ferenc Paulik, Miklos Arnold
  • Patent number: 4801429
    Abstract: A sample handling device for automatically handling a multiplicity of samples, particularly the encapsulated samples for evaluation using a differential scanning calorimeter, on an individual basis. The device comprises a vacuum means, which is capable of transferring a new sample to be substituted for a tested sample, a transfer means, which is capable of removing and replacing a cover means to allow the transfer of the new sample to be substituted for the tested sample.
    Type: Grant
    Filed: July 16, 1987
    Date of Patent: January 31, 1989
    Assignee: Dow Nederland B.V.
    Inventors: Jan C. M. Torfs, Johannes P. M. Laarhoven, Christiaan F. J. Van Heel
  • Patent number: 4606649
    Abstract: A modification to thermogravimetric analyzers with data acquisition devised to allow concurrent TG (thermogravimetry) and DTA (differential thermal analysis) measurements employs three samples mounted close to each other in a TG furnace. Two of the samples are active ones, i.e. of the material to be analyzed, and the third is a reference sample of an inert material. The first active sample is suspended from the beam of a thermobalance. The change in weight of this sample is recorded and plotted versus the temperature of the second active sample. The sample thermocouple and another identical thermocouple are placed in contact with crucibles containing the second active sample and the reference material, respectively. The differential temperature between the sample and the reference material is taken from the two identical thermocouples. The differential signal is amplified and plotted against the temperature of the second active sample.
    Type: Grant
    Filed: January 14, 1985
    Date of Patent: August 19, 1986
    Assignee: Her Majesty the Queen in right of Canada, as represented by the Minister of Energy, Mines and Resources
    Inventor: Shaheer A. Mikhail
  • Patent number: 4594051
    Abstract: A surge detection system for a compressor having a gas inlet and a gas outlet and experiencing rapid temperature changes in said gas inlet during surges, said detector comprising first and second thermocouples having different temperature response times, Tf and Ts respectively, and producing an electrical output proportional to said rapid temperature change occurring during a surge, means for mounting said first and second thermocouples in said compressor gas inlet such that both thermocouples are subject to the same temperature changes, means for electrically coupling said thermocouples to algebraically sum said electrical outputs, Tf-Ts to represent the rapid change in temperature occurring between said thermocouples, and means coupled to said thermocouples for converting said algebraically summed outputs, Tf-Ts, to control signals representing the number, intensity and duration of said surges.
    Type: Grant
    Filed: May 14, 1984
    Date of Patent: June 10, 1986
    Assignee: Dresser Industries, Inc.
    Inventor: John R. Gaston
  • Patent number: 4592661
    Abstract: A heat stress monitor comprised of a thermometer tube having at least a black globe-bulb and a wet-bulb therein and adapted to provide a direct reading of wet-bulb globe temperature (WBGT). The inclusion in the tube of a dry-bulb makes the monitor particularly adapted to measuring WBGT outdoors. The thermometer tube is in the form of a single tube and the bulbs are disposed in series therein with an extension part extending beyond the bulbs to permit a direct reading to be taken of the position of a thermally responsive medium in the tube.
    Type: Grant
    Filed: November 16, 1984
    Date of Patent: June 3, 1986
    Assignee: Dobbie Instruments (Australia) Pty. Ltd.
    Inventor: Bruce L. Wilson
  • Patent number: 4553852
    Abstract: A method for accurate, on site heat flow measurement through a substrate surface using surface mounted heat flow sensors and an apparatus for on site calibration of surface mounted heat flow sensors are presented. The method comprises mounting on the substrate surface a heat flow sensor which is calibrated to establish the relationship between heat flow through the surface and the resultant induced voltage in the sensor under the convective and radiative heat transfer environmental conditions of the surface, measuring the voltage output induced in the sensor by heat flow through the surface, and converting the voltage output to a quantitative heat flow on the basis of the calibration of the sensor. The apparatus of the invention permits the calibration of the sensors under convective and radiative heat transfer environmental conditions which substantially duplicate those of the experimental substrate.
    Type: Grant
    Filed: December 7, 1983
    Date of Patent: November 19, 1985
    Assignee: W. R. Grace & Co.
    Inventors: Gregory Derderian, Robert D. Orlandi, Larry S. Shu, Bahram Siadat
  • Patent number: 4523860
    Abstract: A device for monitoring the amount of butane that can be safely added into a fuel gas before condensation occurs includes a dry-bulb thermocouple for measuring the temperature of the gas and a wet-bulb thermocouple for measuring the temperature of a wick soaked in the butane. For a continuous flowing process the difference in the two measured temperatures indicates the proportion of butane that can be added before saturation, and is used to regulate the flow rate of the butane. The wick is periodically flushed with butane, in order to prevent the heavy hydrocarbon components in the butane from accumulating.
    Type: Grant
    Filed: December 14, 1982
    Date of Patent: June 18, 1985
    Assignee: Chevron Research Company
    Inventors: Thomas G. Chin, Rudy F. Klaver, Arthur Alston
  • Patent number: 4439396
    Abstract: Thermocouple junctions located in the hot and cold regions of an elongated heat conductive body extending through a measurement zone of a power monitoring device, are interconnected in series to provide a differential temperature signal of increased signal strength and fast signal response. The signal is free of the error heretofore arising from asymmetrical axial heat flow through the heat conductive body.
    Type: Grant
    Filed: April 24, 1981
    Date of Patent: March 27, 1984
    Assignee: Scandpower, Inc.
    Inventor: Erik Rolstad
  • Patent number: 4364675
    Abstract: A method for determining the amount of copolymerized vinyl monomer in a acrylonitrile/vinyl monomer copolymer is provided. The method is based on the fact that increasing the vinyl monomer content of the copolymer reduces its melting point. The method consists of first determining the melting point of the copolymer while the copolymer is saturated with water. The presence of water reduces the melting point to a temperature below the range where thermal degradation of the copolymer occurs. The amount of copolymerized vinyl monomer in the copolymer can then be determined by comparing its melting point in the presence of water to that of corresponding copolymers in which the vinyl monomer content thereof is known and varies from copolymer to copolymer.
    Type: Grant
    Filed: March 23, 1981
    Date of Patent: December 21, 1982
    Assignee: Monsanto Company
    Inventor: Bruce G. Frushour
  • Patent number: 4333332
    Abstract: A differential scanning microcalorimeter comprises an adiabatic shell accommodating two capillary calorimetric chambers. One end of each chamber extends beyond the shell and passes through a heat bypass. At least one chamber is contrived in the form of two capillary tubes in thermal contact with each other, with the ends located inside the shell communicating with an end of the other chamber also located inside the shell.
    Type: Grant
    Filed: May 21, 1980
    Date of Patent: June 8, 1982
    Inventor: Peter L. Privalov
  • Patent number: 4327573
    Abstract: A method and apparatus for determining the low temperature characteristics of materials measures the resistivity of a sample material and the resistivity of a comparision material and plots the ratio of the resistivity of the comparision material to the resistivity of the sample material versus the temperature of the sample material. In addition, the method and apparatus measures the temperature of the sample and the temperature of a reference material and plots the difference there between as a function of the temperature of the reference material. The method and apparatus is usable in monitoring and/or controlling lyophilization appartus in order to increase the efficiency of the freeze drying process, that is, increasing product yield while reducing processing time.
    Type: Grant
    Filed: February 29, 1980
    Date of Patent: May 4, 1982
    Assignee: T. A. Jennings Associates, Inc.
    Inventor: Thomas A. Jennings