Abstract: A method for analyzing a minute quantity of a material included in a different material is performed in short extraction treatment without taking a long time and the minute content is rapidly analyzed. The method of analyzing a minute content includes mounting on a sample table a sample piece of a material having a minute content of a different material to be analyzed; dropping onto the sample table a solvent for extracting the minute content from the sample piece, so that the solvent is disposed between the sample table and the sample piece; maintaining at room temperature the solvent between the sample table and the sample piece, and, with the solvent maintained between the sample table and the sample piece, extracting the material of the minute content from the sample piece; and analyzing the content extracted from the sample piece.

Abstract: The present invention provides a method for inhibiting production of copper sulfide in an electrical insulating oil inside an oil-filled electrical apparatus, including adding a benzotriazole compound not having a long-chain alkyl group when the oil-filled electrical apparatus is an open-type oil-filled electrical apparatus, or adding a benzotriazole compound having a long-chain alkyl group when the oil-filled electrical apparatus is a closed-type oil-filled electrical apparatus.

Abstract: The present invention provides a method for inhibiting production of copper sulfide in an electrical insulating oil inside an oil-filled electrical apparatus, including adding a benzotriazole compound not having a long-chain alkyl group when the oil-filled electrical apparatus is an open-type oil-filled electrical apparatus, or adding a benzotriazole compound having a long-chain alkyl group when the oil-filled electrical apparatus is a closed-type oil-filled electrical apparatus.

Abstract: The present invention relates to an electric insulating oil inspection method for determining whether or not an inhibitor-consuming substance is present in an electric insulating oil. The inhibitor-consuming substance is such a substance that causes to decrease over time a concentration of an inhibitor which is added to the electric insulating oil to inhibit copper sulfide from being generated on an insulating paper immersed in the electric insulating oil. The electric insulting oil inspection method includes steps of: preserving the electric insulating oil at a predetermined condition, measuring a concentration of the inhibitor, and determining that the inhibitor-consuming substance is present upon condition that a decrement of the concentration of the inhibitor relative to an initial concentration of the inhibitor becomes not less than a specified amount within a predetermined period.

Abstract: An initial concentration of the residual concentration of a causative substance contained in an insulating oil is compared with a reference value. The causative substance reacts with a conductor forming a winding of an oil-filled electrical device to generate an electrically conductive compound. The reference value is defined as a value for determining whether a main determinant that determines the lifetime of the oil-filled electrical device is generation of the electrically conductive compound or degradation of insulating paper. Based on the initial concentration of the causative substance and the reference value, the lifetime of the oil-filled electrical device is assessed.

Abstract: Provided is a diagnosis method for an oil-filled electrical apparatus, which is for evaluating the degree of danger of copper sulfide being generated within the oil-filled electrical apparatus, comprising: a first step for detecting a specific compound contained within insulating oil inside the oil-filled electrical apparatus; a second step for evaluating the possibility of copper sulfide being generated inside the oil-filled electrical apparatus, on the basis of the result detected by the first step; and a third step for diagnosing the degree of danger of a malfunction occurring in the oil-filled electrical apparatus, on the basis of the evaluation result obtained in the second step. The specific compound contains dibenzyl disulfide and/or a reaction product of a radical resulting from dibenzyl disulfide, and di-tert-butyl-p-cresol and/or a reaction product of a radical resulting from di-tert-butyl-p-cresol, or, di-tert-butyl-phenol and/or a reaction product of a radical resulting from di-tert-butyl-phenol.

Abstract: An oil immersed electrical apparatus such as an oil immersed transformer that can detect copper sulfide precipitated on coil insulating paper is provided. In the oil immersed transformer in which a coil with its surface covered by insulating paper is arranged in a container filled with insulating oil, a detection member is prepared by providing two electrodes on a surface of a plate-like pressboard formed of cellulose, which is a same material as that of the insulating paper, this detection member is arranged in contact with the insulating oil, and generation of copper sulfide is detected from reduction in a surface resistance between the electrodes. The temperature of the detection member is set higher than the temperature of the coil so that copper sulfide is generated thereon prior to generation of copper sulfide on a coil unit.

Abstract: A method allowing an accurate diagnosis of a failure of an oil-filled electrical apparatus resulting from production of copper sulfide even with a small amount of an insulating oil is implemented. A diagnostic method for an oil-filled electrical apparatus for diagnosing a failure of the oil-filled electrical apparatus having a copper part disposed in an insulating oil is implemented by detecting at least one compound of bibenzyl and dibenzyl sulfide in the oil of the oil-filled electrical apparatus, to diagnose a failure of the oil-filled electrical apparatus in accordance with the detected amount of the compound. It is configured such that a failure of the oil-filled electrical apparatus resulting from production of copper sulfide can be diagnosed by detecting a specified substance, which allows an accurate diagnosis of a failure even with a small amount of the insulating oil.

Abstract: To obtain water-dispersible varnish used in an alternative refrigerant/refrigerating machine oil refrigerant system or a natural refrigerant/refrigerating machine oil refrigerant system, the water-dispersible varnish being capable of solving two problems, namely, reducing the volatile components and the like during thermal curing and resistance of the cured varnish to the refrigerant system. Water-dispersible varnish having a specific thermosetting resin as base polymer, a specific vinyl monomer as reactive diluent, organic peroxide as reaction initiator, and water mixed therein.

Abstract: A method for predicting the possibility of occurrence of an anomaly includes compositionally analyzing an insulating oil collected from a transformer in operation, calculating an estimated value of a concentration of dibenzyl disulfide in the insulating oil in its virgin state from the compositional analysis, and predicting the possibility of occurrence of anomaly in the oil-filled electrical apparatus from the level of the estimated value.

Abstract: An initial concentration of the residual concentration of a causative substance contained in an insulating oil is compared with a reference value. The causative substance reacts with a conductor forming a winding of an oil-filled electrical device to generate an electrically conductive compound. The reference value is defined as a value for determining whether a main determinant that determines the lifetime of the oil-filled electrical device is generation of the electrically conductive compound or degradation of insulating paper. Based on the initial concentration of the causative substance and the reference value, the lifetime of the oil-filled electrical device is assessed.

Abstract: An oil immersed electrical apparatus such as an oil immersed transformer that can detect copper sulfide precipitated on coil insulating paper is provided. In the oil immersed transformer in which a coil with its surface covered by insulating paper is arranged in a container filled with insulating oil, a detection member is prepared by providing two electrodes on a surface of a plate-like pressboard formed of cellulose, which is a same material as that of the insulating paper, this detection member is arranged in contact with the insulating oil, and generation of copper sulfide is detected from reduction in a surface resistance between the electrodes. The temperature of the detection member is set higher than the temperature of the coil so that copper sulfide is generated thereon prior to generation of copper sulfide on a coil unit.

Abstract: An object of the invention is to provide a diagnostic method for an oil-filled electrical device that considers a temperature distribution in the oil-filled electrical device and enables accurate diagnosis to be conducted even when the method is applied to diagnosis of an actually operating device, and further provide a method with which such diagnosis of an oil-filled electrical device can be conducted from a component analysis value of an insulating oil in the oil-filled electrical device. The invention is a diagnostic method for an oil-filled electrical device including in an insulating oil a metal part wrapped with insulating paper, and determines that a time when a surface resistivity of a maximum precipitation site where metal sulfide is most precipitated on the insulating paper reaches a preset surface resistivity management value is a time of occurrence of an abnormality.

Abstract: A method allowing an accurate diagnosis of a failure of an oil-filled electrical apparatus resulting from production of copper sulfide even with a small amount of an insulating oil is implemented. A diagnostic method for an oil-filled electrical apparatus for diagnosing a failure of the oil-filled electrical apparatus having a copper part disposed in an insulating oil is implemented by detecting at least one compound of bibenzyl and dibenzyl sulfide in the oil of the oil-filled electrical apparatus, to diagnose a failure of the oil-filled electrical apparatus in accordance with the detected amount of the compound. It is configured such that a failure of the oil-filled electrical apparatus resulting from production of copper sulfide can be diagnosed by detecting a specified substance, which allows an accurate diagnosis of a failure even with a small amount of the insulating oil.

Abstract: A sample preparation for analyzing a minute quantity of a content included in a material is performed by short-time extraction treatment without long-time extraction treatment, and the minute quantity of the content in the material is rapidly analyzed. The method of analyzing a minute quantity of a content includes mounting on a sample table a sample piece of a material to be analyzed; dropping onto the sample table the solvent for extracting the content from the sample piece, and injecting the solvent into a gap between the sample table and the sample piece; maintaining at room temperature the solvent injected into the gap between the sample table and the sample piece, and, with the solvent maintained in the gap between the sample table and the sample piece, extracting the content from the sample piece; and analyzing the content extracted from the sample piece.

Abstract: A refrigerant circulating system that uses a highly polar refrigerant, as typified by a hydrofluorocarbon-based one, and a refrigerating oil that has slight solubility with a liquid refrigerant on the condensation side. Also, a refrigerant circulating cycle that uses a highly polar refrigerant, as typified by a hydrofluorocarbon-based one, and a refrigerating oil that has a slight solubility with a liquid refrigerant and which has a greater specific gravity than the liquid refrigerant. Thereby, it provides a high electrical insulation and moisture resistance, good oil return to the compressor, and high reliability.

Abstract: A method of assembling a closed loop refrigerating air conditioning system using a hydrofluorocarbon refrigerant by applying a first oil which is insoluble with the hydrocarbon refrigerant to components of a compressor, and storing the insoluble oil within the housing of the compressor in a single or mixed state.

Abstract: A refrigeration device comprising a compressor, a condenser, an evaporator, an accumulator and a refrigerant is described. Lubricating oil present in the compressor is chosen so as to be insoluble with the refrigerant, and a particular accumulator design is described to ensure return of oil back to the compressor.

Abstract: The present invention is directed at a novel side outer panel construction which includes a front panel having a front door opening and a first center pillar forming portion in its rear end. The present invention further includes a rear panel having a rear door opening and a second center pillar forming portion in its front end.

Abstract: A method of manufacturing a double-structure sound absorbing wall having a cavity defined by joining first and second plate members, comprising the steps of providing said first and second plate members with gas bleeding holes and recesses depressed toward the inside of said cavity to abut the members to each other, providing a sound insulating member foamable by heat received in said cavity with relief holes for spot-welding corresponding to said cavity, holding said sound insulating member by said recesses upon abutting of said plate members, abutting said peripheral edges to each other, spot-welding said recesses to each other to close said cavity, and foaming said sound insulating member by heating to fill said cavity therewith.