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dc.contributor.advisorMarkus Zahn.en_US
dc.contributor.authorAmin, M. Shahrooz, 1981-en_US
dc.contributor.otherMassachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science.en_US
dc.date.accessioned2005-09-27T18:01:35Z
dc.date.available2005-09-27T18:01:35Z
dc.date.issued2004en_US
dc.identifier.urihttp://hdl.handle.net/1721.1/28730
dc.descriptionThesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004.en_US
dc.description"Spetember 2004."en_US
dc.descriptionIncludes bibliographical references.en_US
dc.description.abstract(cont.) above atmospheric pressure caused both positive current and negative current pulses with the negative pulse larger than the positive pulse. A pressure decrease of more than 10psi below atmospheric pressure also caused both positive current and negative current pulses with the positive current larger than the negative current pulse. Experiments showed that the negative current was generated by the galvanic action between the two dissimilar metals in the triaxial connector connecting the center electrode of the electrode chamber with the electrometer, as water condensed. Positive current could have been produced by the evaporation of moisture from the center electrode of the electrode chamber. Dew point analysis is performed to show that for water to condense on metallic surfaces, it is not necessary to reach the dew point. The calculated dew point temperature is lower than the temperature at which the water condenses upon the electrode surfaces. In the liquid and solid dielectric experiments, we use a patented Faraday cage which is composed of two identical in-line hollow, gold-plated Faraday cup electrodes that enclose the samples which move between them during each measurement under computer control. We conducted charge measurements using various electrometers to rule out the possibility of false instrument readings due to input offset voltage and other experimental effects. One wire mesh style of Faraday cage connected with an electrometer was also used to measure the charge. The liquid dielectrics are distilled water, tap water, Sargasso Sea water ...en_US
dc.description.abstractThis thesis is devoted to Faraday cage measurements of air, liquid, and solid dielectrics. Experiments use pressurized air with fixed Faraday cage electrodes, and a moving sample of liquid and solid dielectrics between two Faraday cup electrodes. Extensive experiments were conducted to understand the source of the unpredictable net measured charge. In the air experiment, the Faraday cage consists of a hollow, cylindrical, gold-plated brass electrode mounted within a gold-plated brass hermetic chamber that connects with earth ground. Measurements of transient current at various temperatures and humidity during transient air pressure change are presented. The flow of electrode current is shown not to be due to capacitance and input offset voltage changes, since the calculated value is on the order of 10⁻¹⁶ Amperes which is much less than the measured currents of order 10⁻¹³ Amperes. By controlling the internal relative humidity of air in the Faraday cage, and from the measurements of current using dry nitrogen, we confirm that the absence of moisture causes no current to flow. Amplitude of the measured current is found to be dependent upon the internal relative humidity. Repeatedly, polarity reversals were observed to occur, in part due to galvanic action between dissimilar metals as water condensed upon the insulating surface between them. At a low temperature with a small pressure change, only one pulse of current was observed to occur but, with a pressure change of more than l0psi, two opposite polarity pulses of current were shown to occur almost simultaneously. A small pressure increase only caused a pulse of negative current, and a small pressure decrease only caused a pulse of positive current. A pressure increase of more than l0psien_US
dc.description.statementofresponsibilityby M. Shahrooz Amin.en_US
dc.format.extent117 leavesen_US
dc.format.extent7105429 bytes
dc.format.extent7119908 bytes
dc.format.mimetypeapplication/pdf
dc.format.mimetypeapplication/pdf
dc.language.isoen_US
dc.publisherMassachusetts Institute of Technologyen_US
dc.rightsM.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.en_US
dc.rights.urihttp://dspace.mit.edu/handle/1721.1/7582
dc.subjectElectrical Engineering and Computer Science.en_US
dc.titleAdvanced Faraday cage measurements of charge, short-circuit current and open-circuit voltageen_US
dc.typeThesisen_US
dc.description.degreeS.M.en_US
dc.contributor.departmentMassachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science.en_US
dc.identifier.oclc59554613en_US


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