5.1 Values obtained by flexural test provides information with regard to the bond strength of the particular varnish in combination with a particular type of magnet wire, when measured under conditions described in this test method.1.1 This test method covers the determination of the bond strength of an electrical insulating varnish when applied to a twisted coil of film-insulated magnet wire. The use of a particular type of film-insulated wire will show the values for that combination of film coating and varnish.1.2 The values stated in inch-pound units are the standard. The values given in parentheses are for information only.NOTE 1: Although this standard and Method C of IEC 61033 differ in approach or detail, data obtained using either are technically equivalent.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. A specific precautionary statement is given in Section 7.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 515元 / 折扣价： 438 元 加购物车

1.1 This test method covers the determination of the thermal failure of solid electrical insulating materials subjected to electric stress at commercial power frequencies. This test method has been developed for testing materials such as certain glasses and ceramics, that exhibit large increases in dielectric loss with increasing temperature.1.2 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. A specific hazard statement is given in 10.1.

定价： 0元 / 折扣价： 0 元

定价： 260元 / 折扣价： 221 元 加购物车

5.1 United States governmental regulations mandate that electrical apparatus and electrical insulating fluids containing PCB be handled and disposed of through specific procedures. The procedure to be used for a particular apparatus or quantity of insulating fluid is determined by the PCB content of the fluid. The results of this analytical technique can be useful in selecting the appropriate handling and disposal procedure.5.2 Quantification in this technique requires a peak-by-peak comparison of the chromatogram of an unknown specimen with that of standard Aroclor test specimens obtained under identical conditions. The amount of PCB producing each peak in the standard chromatogram shall be known independently.5.3 The technique described is based on data for standard chromatograms of Aroclors 1242, 1254, and 1260 obtained using specific chromatographic column packing materials and operating conditions.4 Relevant chromatograms are reproduced in Fig. 1, Fig. 2, and Fig. 35, for isothermal packed columns and in Figs. X4.1 through X4.3) for temperature programmed mega-bore capillary columns. Each peak is identified by its retention time relative to that of a standard. The types and amounts of PCB associated with each peak have been determined by mass spectroscopy and are given in Table 1, Table 2, and Table 3.4 Other chromatographic operating conditions, and in particular, other column packing materials, may give different separations. The data given in the tables should not be used if chromatograms of the standards differ significantly from those shown in the figures. The peaks in such standard chromatograms shall be independently identified and quantified.5.4 Different isomers of PCB with the same number of chlorine substituents can cause substantially different responses from EC detectors. Mixtures of PCB containing the same amount of PCB, but with a different ratio of isomers, can give quite different chromatograms. This technique is effective only when the standard PCB mixtures and those found in the unknown test specimen are closely related. Aroclors 1242, 1254, and 1260 are adequate standards because they have been found to be the most common PCB contaminant in electrical insulating oils.1.1 This test method describes a quantitative determination of the concentration of polychlorinated biphenyls (PCBs) in electrical insulating liquids by gas chromatography. It also applies to the determination of PCB present in mixtures known as askarels, used as electrical insulating liquids.1.2 The PCB mixtures known as Aroclors2 were used in the formulation of the PCB-containing askarels manufactured in the United States. This test method may be applied to the determination of PCBs in insulating liquids contaminated by either individual Aroclors or mixtures of Aroclors. This technique may not be applicable to the determination of PCBs from other sources of contamination.1.3 The precision and bias of this test method have been established only for PCB concentrations in electrical insulating mineral oils and silicones. The use of this test method has not been demonstrated for all insulating fluids. Some insulating liquids, such as halogenated hydrocarbons, interfere with the detection of PCBs and cannot be tested without pretreatment.1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 646元 / 折扣价： 550 元 加购物车

4.1 The resistivity of a liquid is a measure of its electrical insulating properties under conditions comparable to those of the test. High resistivity reflects low content of free ions and ion-forming particles, and normally indicates a low concentration of conductive contaminants.1.1 This test method covers the determination of specific resistance (resistivity) applied to new electrical insulating liquids, as well as to liquids in service, or subsequent to service, in cables, transformers, circuit breakers, and other electrical apparatus.1.2 This test method covers a procedure for making referee tests with dc potential.1.3 When it is desired to make routine determinations requiring less accuracy, certain modifications to this test method are permitted as described in Sections 19 – 26.1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. See 17.4.3 for a specific warning statement.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 590元 / 折扣价： 502 元 加购物车

This specification covers two types of new mineral insulating oils of petroleum origin for use as an insulating and cooling medium in new and existing power and distribution electrical apparatuses, such as transformers, regulators, reactors, circuit breakers, switchgear, and attendant equipment. It is the intension of this specification to define a mineral insulating oil that is functionally interchangeable and miscible with existing oils, is compatible with existing apparatus and with appropriate field maintenance, and will satisfactorily maintain its functional characteristics in its application in electrical equipment. Type I mineral oils are used for apparatuses where normal oxidation resistance is required, where as, Type II mineral oils are used for apparatuses where greater oxidation resistance is required. When examined with corresponding test methods, sampled specimens shall conform accordingly to physical (aniline point, color, flash point, interfacial tension, pour point, relative density or specific gravity, viscosity, and appearance), electrical (dielectric breakdown voltage, gassing tendency, and dissipation or power factor), and chemical (oxidation stability, oxidation inhibitor content, corrosive sulfur content, water content, neutralization number, and PCB content) property requirements.1.1 This specification covers unused mineral insulating oil of petroleum origin for use as an insulating and cooling medium in new and existing power and distribution electrical apparatus, such as transformers, regulators, reactors, circuit breakers, switchgear, and attendant equipment.1.2 This specification is intended to define a mineral insulating oil that is functionally interchangeable and miscible with existing oils, is compatible with existing apparatus and with appropriate field maintenance,2 and will satisfactorily maintain its functional characteristics in its application in electrical equipment. This specification applies only to new insulating oil as received prior to any processing.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 590元 / 折扣价： 502 元 加购物车

4.1 This test method is used to determine the compressive strength of hardened lightweight insulating concrete using samples taken from the field. The test results can be used to determine specification compliance when results of tests on specimens molded at the time of construction are not available or are defective, and to establish the strength properties of existing construction.1.1 This test method covers obtaining, preparing, and testing specimens of hardened, lightweight, insulating concrete made with either lightweight aggregate conforming to Specification C332 or using preformed foam made from a foaming agent conforming to Specification C869/C869M and having an oven-dry density not exceeding 800 kg/m3 [50 lb/ft3].1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 515元 / 折扣价： 438 元 加购物车

This specification covers pressboard for electrical insulating purposes as well as for dielectrical or structural purposes in transformers and other electrical apparatus. Pressboards under this specification are of three types: Type 1 consists of high-purity (Grade 1.1) calendered pressboards, while Type 2 consists of normal-purity (Grades 2.1.1, 2.2.1, 2.3.1, and 2.3.2) calendered pressboards. Precompressed pressboards (Grades 3.1.1, 3.2.1, and 3.3) fall under Type 3. Not included in this specification, however, are pressboards comprised of two or more sheets laminated together using an adhesive. Pressboards shall be manufactured from unbleached kraft pulp, cotton pulp, or a combination of both, and shall conform to the thickness, density, surface texture (smooth calendered surface for Types1 and 2, and fine-textured finish for Type 3), and color (from tan to blue-gray, depending on the pressboard's grade) requirements specified. The pressboard must also be free of dirt, metal particles, and other foreign material. Tests for apparent density, thickness, moisture and ash content, aqueous extract conductivity, chloride content, tensile strength, pH of aqueous extract, dielectric strength in air and in oil, shrinkage, and compressibility shall be performed and shall conform to the requirements specified.1.1 This specification covers pressboard for electrical insulating purposes, manufactured from kraft, cotton, or kraft and cotton pulps. This board is intended for dielectrical or structural purposes in transformers and other electrical apparatus.1.2 Electrical insulating boards are most commonly referred to (and will be referred to herein) as pressboard. Other terms used for pressboard include transformer board, fuller board, and presspan.1.3 This specification covers pressboard having a nominal thickness of 0.030 to 0.315 in. (0.8 to 8.0 mm). For thinner material refer to Specification D1305.1.4 The maximum thickness available will differ with the type and the manufacturer. The maximum sheet size will differ with the thickness, type, and manufacturer.1.5 Pressboard shall normally be plied wet without pasting. Unless specified by the purchaser, this specification does not include pressboard comprised of two or more sheets that have been laminated together using an adhesive.NOTE 1: The materials described in this specification are similar to corresponding types of pressboard described in IEC Specification 641-3, Sheet 1, Types B.0.1, B.2.1, B.2.3, B.3.1, and B.3.3.1.6 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 515元 / 折扣价： 438 元 加购物车

This specification covers the in-service care, inspection, testing, and use voltage of insulating gloves and sleeves for protection from electrical shock. Gloves and sleeves covered under this specification are designated as type I or type II; class 00, class 0, class 1, class 2, class 3, or class 4. Type I - nonresistant to ozone, made from a high-grade cis-1,4-polyisoprene rubber compound of natural or synthetic origin, properly vulcanized, and type II - ozone resistant, made of any elastomer or combination of elastomeric compounds. The recommended sequence of inspection and testing of gloves and sleeves at an electrical testing facility are: check-in, washing, and preliminary inspection; repair; electrical test; drying; final inspection; record-keeping and marking; and powdering, pairing, and packing for storage or shipment. Electrical testing shall be performed to meet the requirements prescribed.1.1 This specification covers the in-service care, inspection, testing, and use voltage of insulating gloves and sleeves for protection from electrical shock.1.2 The values stated in SI units are to be regarded as the standard. See IEEE/ASTM SI-10.1.3 The following safety hazards caveat pertains only to the test method portion, Sections 6 and 7, of this specification. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For a specific warning statement, see 7.2.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 590元 / 折扣价： 502 元 加购物车

This guide describes methods of testing and specifications for electrical insulating oils of petroleum origin intended for use in electrical cables, transformers, oil circuit breakers, and other electrical apparatus where the oils are used as insulating, or heat transfer media, or both. This guide is classified into the following categories: sampling practices, physical tests, electrical tests, chemical tests, and specifications. The test methods shall be as follows: aniline point; coefficient of thermal expansion; color; examination; flash and fire point; interfacial tension; pour point of petroleum products; refractive index; relative density; specific heat; thermal conductivity; turbidity; viscosity; dielectric breakdown voltage; dissipation factor and relative permittivity; gassing tendency; resistivity; stability under electrical discharge; acidity; carbon-type composition; compatibility with construction material; copper content; furanic compounds; gas analysis; gas content; inorganic chlorides and sulfates; neutralization numbers; oxidation inhibitor content; oxidation stability; polychlorinated biphenyl content; sediment and soluble sludge; sulfur; water content; mineral insulating oil for electrical apparatus; and high firepoint electrical insulating oils.1.1 This guide describes methods of testing and specifications for electrical insulating liquids intended for use in electrical cables, transformers, liquid-filled circuit breakers, and other electrical apparatus where the liquids are used as insulating, or heat transfer media, or both.1.2 The purpose of this guide is to outline the applicability of the available test methods. Where more than one is available for measuring a given property, their relative advantages are described, along with an indication of laboratory convenience, precision, (95 % confidence limits), and applicability to specific types of electrical insulating liquids.1.3 This guide is classified into the following categories: Sampling Practices, Physical Tests, Electrical Tests, Chemical Tests, and Specifications. Within each test category, the test methods are listed alphabetically by property measured. A list of standards follows:Category Section ASTM StandardSampling:  3 D923Physical Tests:     Aniline Point  4 D611 Coefficient of Thermal Ex-  pansion  5 D1903 Color  6 D1500 Examination: Visual Infrared  7 D1524, D2144, D2129 Flash and Fire Point  8 D92 Interfacial Tension  9 D971 Pour Point of Petroleum  Products 10 D97, D5949, D5950 Particle Count in Mineral  Insulating Oil 11 D6786 Refractive Index and Specific  Optical Dispersion 12 D1218 Relative Density (Specific  Gravity) 13 D287, D1217, D1298, D1481, D4052 Specific Heat 14 D2766 Thermal Conductivity 15 D2717 Viscosity 16 D445, D2161, D7042Electrical Tests:     Dielectric Breakdown Voltage 17 D877, D1816, D3300 Dissipation Factor and Rela-  tive Permittivity (Dielectric   Constant) 18 D924Gassing Characteristic  Under Thermal Stress 19 D7150 Gassing Tendency 20 D2300 Resistivity 21 D1169Chemical Tests:     Acidity, Approximate 22 D1534 Carbon-Type Composition 23 D2140 Compatibility with Construc-  tion Material 24 D3455 Copper Content 25 D3635 Elements by Inductively  Coupled Plasma (ICP-AES) 26 D7151 Furanic Compounds in  Electrical Insulating Liquids 27 D5837 Dissolved Gas Analysis 28 D3612 Gas Content of Cable and  Capacitor Liquids 29 D831, D1827, D2945 Neutralization (Acid and  Base) Numbers 30 D664, D974 Oxidation Inhibitor Content 31 D2668, D4768 Oxidation Stability 32 D1934, D2112, D2440 Polychlorinated Biphenyl  Content (PCB) 33 D4059 Sulfur, Corrosive 34 D1275 Water Content 35 D1533Specification:     Mineral Insulating Liquid for  Electrical Apparatus 36 D3487 Less Flammable Electrical  Insulating Liquids 37 D5222 Silicone Fluid used for Electrical  Insulation 38 D4652 Natural (Vegetable Oil) Ester   Fluids used in Electrical  Apparatus 39 D68711.4 The values stated in SI units are to be regarded as standard. The values stated in parentheses are provided for information only.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 646元 / 折扣价： 550 元 加购物车

5.1 Certain gases have excellent dielectric and electric arc interruption characteristics which make their use in electrical installations very desirable.5.2 Water content, as the test parameter, is of great importance in determining the dielectric effectiveness of the gas. Under certain conditions, water may condense and become a conducting liquid resulting in a catastrophic dielectric breakdown of the insulation. The water content of these insulating gases as expressed by dew point is listed in Specifications D1933, D2472, and D3283.5.3 Once the dew point is determined, a conversion to moisture content may be performed using Table 1. Once moisture content is known, the lowest temperature at which gas insulated equipment can be safely operated can usually be determined by reviewing manufacturers' specifications for the equipment.(A) Vapor pressures in atmospheres at various dew points can be obtained by dividing the values for “volume percent'' in this table by 100. Calculations for this table were made by using the International Critical Table values for the vapor pressure of ice and liquid water. The vapor pressure of liquid water was used for values from 50 to 0°C. The vapor pressure of ice was used from 0 to − 81°C.5.4 The dew point of the test gas is independent of the gas temperature but does depend on its pressure. Many moisture measurement test instruments are sensitive to pressure, and display moisture values at the instrument inlet pressure and not necessarily at the pressure of the system being sampled. It is therefore important to account for this condition to avoid serious measurement errors.1.1 These test methods describe the determination of the water vapor content of electrical insulating gases by direct or indirect measurement of the dew point and the calculation of the water vapor content.1.2 The following four test methods are provided:1.2.1 Method A describes the automatic chilled mirror method for measurement of dew point as low as − 73°C (−99°F).1.2.2 Method B describes the manual chilled mirror or dew cup method for measurement of dew point as low as − 73°C (−99°F).1.2.3 Method C describes the adiabatic expansion method for measurement of dew point as low as − 62°C (−80°F).1.2.4 Method D describes the capacitance method for measurement of dew point as low as − 110°C (−166°F).1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific warnings, see 8.1.1, 9.2, 10.1.2 and 10.2.5.

定价： 590元 / 折扣价： 502 元 加购物车

5.1 Methanol and ethanol are generated by the degradation of cellulosic materials used in the solid insulation systems of electrical equipment. More particularly, methanol comes from the depolymerization of cellulosic materials.3, 4, 5, 65.2 Methanol and ethanol, which are soluble in an insulating liquid to an appreciable degree, will proportionally migrate to that liquid after being produced from the cellulose.5.3 High concentrations or unusual increases in the concentrations of methanol or ethanol, or both, in an insulating liquid may indicate cellulose degradation from aging or incipient fault conditions. Testing for these alcohols may be used to complement dissolved gas-in-oil analysis and furanic compounds as performed in accordance with Test Methods D3612 and D5837 respectively.1.1 This test method describes the determination of by-products of cellulosic materials degradation found in electrical insulation systems that are immersed in insulating liquid. Such materials include paper, pressboard, wood and cotton materials. This test method allows the analysis of methanol and ethanol from the sample matrix by headspace GC-MS or GC-FID.1.2 This test method has been used to test for methanol and ethanol in mineral insulating liquids and less flammable electrical insulating liquids of mineral origin as defined in D3487 and D5222 respectively. Currently, this method is not a practical application for ester liquids.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 590元 / 折扣价： 502 元 加购物车

4.1 This standard provides recommendations for the installation in a safe and effective manner. Actual conditions may vary greatly, and additional care should be taken to ensure a safe and effective installation.4.2 This standard presents requirements that are general in nature and considered practical. They are not intended as specific recommendations. The user should consult the manufacturer for recommended application methods and procedures.4.3 This standard does not address the applicability of regulatory limitations. This is the responsibility of the user.1.1 This practice covers the requirements for storing, handling, and application of cellulosic fiber insulating board products.1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 515元 / 折扣价： 438 元 加购物车

5.1 Dissipation Factor and Relative Permittivity—Knowledge of these properties is important in the design of electrical equipment such as cables, transformers, insulators, and so forth. The numerical product of these two properties of a dielectric system is proportional to the energy loss converted to heat, and is called its loss index (see Terminology D1711). The energy loss reduces the efficiency of electrical equipment. The heat produced tends to chemically degrade the dielectric material and may even lead to thermal runaway. Test results of impregnated specimens can disclose significant differences between combinations of papers and oils that appear similar when the papers and the oils are tested separately. Dissipation factor, particularly at elevated temperatures, is often changed significantly by the presence of a small quantity of impurities in either the liquid or the paper. This practice is useful in the comparison of materials and in evaluating the effects of different papers on a given liquid. Judicious analysis of results with respect to time, temperature, and field strength are useful in predicting the performance and capabilities of systems using the paper and the liquid. For additional information on the significance of dissipation factor and relative permittivity, see Test Methods D150.5.2 Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at Commercial Power Frequencies: 5.2.1 A comprehensive discussion of the significance of the dielectric strength test as applied to solid, semi-solid, and liquid materials is given in Appendix X1 of Test Method D149. Other factors peculiar to high-quality composite insulations, such as oil-impregnated papers, are considered in the following:5.2.2 In tests involving high electrical stresses, immersion of critical parts of a test circuit in oil is a widely used technique for inhibiting corona. However, it has limitations that must be recognized when using the submerged electrode option of this practice (Note 1). Attack on the paper by corona generated in the surrounding fluid at electrode edges can occur whether the fluid is air or oil. Corona occurs at considerably higher voltages in oil than in air. Thick and dense papers are more likely to cause discharge-initiated breakdowns. For interpretation of breakdown measurements consider the number of edge breakdowns, implying discharge-initiated breakdowns.NOTE 1: Two techniques are in use in the industry for testing specimens for dielectric breakdown voltage. In one, the test is made with the electrodes and test specimen submerged in the impregnating liquid while in the other the electrodes are not submerged, that is, the specimen is tested in air. Much data has been accumulated using the latter technique. These techniques yield different values of breakdown voltage. Test Method D149 states preference for testing materials in the medium in which they are used. The use of submerged electrodes follows this preference. When testing thick insulating boards, the use of submerged electrodes is greatly preferred.5.2.3 The results of power frequency tests on oil impregnated papers are useful for screening, research, and quality control, provided that considerable judgment is exercised in interpreting the results. The application of the test results to equipment design and service requires particular caution and skill (see Appendix X1 of Test Method D149).5.3 Dielectric Breakdown Voltage and Dielectric Strength Under Impulse Conditions—Testing impregnated paper or board under impulse conditions can yield useful data for the designer of electrical equipment. The test results are useful in the comparison of materials and for research studies. For a more general treatise on the significance of impulse testing see Test Method D3426.1.1 This practice covers the preparation of insulating paper and board impregnated with a liquid dielectric. Where this practice states only “paper,” the same procedure shall apply to board.1.2 This practice has been found practicable for papers having nominal thickness of 0.05 mm (2 mil) and above. It has been used successfully for insulating board as thick as 6 mm (1/4 in.) when care is taken to ensure the specimen geometry necessary for valid measurement of dielectric properties. Suitable geometry depends on the electrode system used. Rigid solid opposing electrodes require flat specimens that have essentially parallel surfaces.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 515元 / 折扣价： 438 元 加购物车

This specification covers thermal insulating bricks made from fire clay that are used as backup insulation for refractory furnace linings of boiler furnaces. The bricks shall be composed of heat-resistant materials that have been burned or fired to produce the desired density, strength, and structure. Representative bricks shall be tested, and shall conform accordingly to specified values of bulk density, modulus of rupture, and reheat change.1.1 This specification covers two types of thermal insulating brick for industrial or marine boiler furnaces. Type I is a special, 2500 °F (1371 °C) maximum service temperature, insulating firebrick that is used as backup insulation for refractory furnace linings.2 Type II is a standard insulating brick that, in general, is used where there may be direct contact with combustion gases, such as forge and stress relieving furnaces.31.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 590元 / 折扣价： 502 元 加购物车