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4.1 Materials less than or equal to 15 mm (0.59 in.) in thickness shall not be tested in accordance with this test method in order to avoid complete immersion of the specimens. This type of exposure is beyond the scope of this test method.4.2 This test method is used to assess both the short-term water retention and the long-term water retention. The short-term water retention is assessed as the average of the water retained following partial immersion intervals of 0.75-h and 3.00-h, in kilograms per square meter (percent by volume) (for materials tested at 25.4 mm (1.00 in.) thickness). The long-term water retention is assessed as the water retained following a 168-h partial immersion interval, in kilograms per square meter (percent by volume) (for materials tested at 25.4 mm (1.00 in.) thickness).4.3 Materials shall be tested at both actual product thickness and 25.4 mm (1.00 in.) thickness provided the materials can be cut to a thickness of 25.4 mm (1.00 in.) without changing the original character of the materials. If a product cannot be cut without changing the original character of the material, the corresponding information shall be provided in the test report. Results shall be reported on the basis of equal nominal wetted specimen surface area (in units of kilograms per square meter) for materials tested at actual product thickness and on the basis of equal specimen volume (in units of percent by volume) for materials tested at 25.4 mm (1.00 in.) thickness. If a product cannot be cut to a thickness of 25.4 mm (1.00 in.) or if the actual product thickness is less than 25.4 mm (1.00 in.) but greater than 15 mm (0.59 in.), the product shall only be tested at actual product thickness and results only reported on the basis of equal nominal wetted specimen surface area.4.3.1 By reporting results on the basis of equal nominal wetted specimen surface area, specimens of different thicknesses can be compared equitably. For some specimens, the water intake and retention primarily depends on the nominal wetted surface area available for water intake.4.3.2 By reporting results on the basis of equal specimen volume, specimens can be compared equitably using units that commonly are selected to represent results of water intake testing (percent by volume). For some materials, water intake and retention primarily depends on the volume of the specimen available for water intake.4.3.3 In most cases water retention is a secondary performance characteristic that has an influence on a primary performance characteristic, such as thermal performance, surface accumulation of moisture (that will potentially contribute to fungal growth), or localized collection of electrolytes (that will potentially contribute to corrosion). Depending on the primary performance characteristic that is of interest, the preferred units for use in comparing the water retention of different materials will be either kilograms per square meter or percent by volume.4.4 Immersion times in addition to those required by this test method shall be permitted to be selected provided that all parties involved are in agreement.4.5 The water retention characteristics of materials will potentially be affected by conditions such as elevated temperatures or chemical exposures.1.1 This test method determines the amount of water retained (including surface water) by rigid block and board thermal insulations used in building construction applications after these materials have been partially immersed in liquid water for prescribed time intervals under isothermal conditions. This test method is intended to be used for the characterization of materials in the laboratory. It is not intended to simulate any particular environmental condition potentially encountered in building construction applications.1.2 This test method does not address all the possible mechanisms of water intake and retention and related phenomena for rigid thermal insulations. It relates only to those conditions outlined in 1.1. Determination of moisture accumulation in thermal insulations due to complete immersion, water vapor transmission, internal condensation, freeze-thaw cycling, or a combination of these effects requires different test procedures.1.3 Each partial immersion interval is followed by a brief free-drainage period. This test method does not address or attempt to quantify the drainage characteristics of materials. Therefore, results for materials with different internal structure and porosity, such as cellular materials and fibrous materials, are not necessarily directly comparable. Also, test results for specimens of different thickness are not necessarily directly comparable because of porosity effects. The surface characteristics of a material also affect drainage. It is possible that specimens with rough surfaces will retain more surface water than specimens with smooth surfaces, and that surface treatment during specimen preparation will affect water intake and retention. Therefore, it is not advisable to directly compare results for materials with different surface characteristics.1.4 For most materials the size of the test specimens is small compared with the size of the products actually installed in the field. If the surface-to-volume ratios for the test specimens and the corresponding products are different, it is possible that the test results will be misleading.1.5 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to inch-pound units that are provided for information only and are not considered standard.1.6 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.1.7 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.

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5.1 Assumptions: 5.1.1 Control well discharges at a constant rate, Q.5.1.2 Control well is of infinitesimal diameter and partially penetrates the aquifer.5.1.3 The nonleaky artesian aquifer is homogeneous, and aerially extensive. The aquifer may also be anisotropic and, if so, the directions of maximum and minimum hydraulic conductivity are horizontal and vertical, respectively. The methods may be used to analyze tests on unconfined aquifers under conditions described in a following section.NOTE 1: Slug and pumping tests implicitly assume a porous medium. Fractured rock and carbonate settings may not provide meaningful data and information.5.1.4 Discharge from the well is derived exclusively from storage in the aquifer.5.1.5 The geometry of the assumed aquifer and well conditions are shown in Fig. 2.5.2 Implications of Assumptions—The vertical flow components in the aquifer are induced by a control well that partially penetrates the aquifer, that is, a well that is not open to the aquifer through its full thickness. The effects of vertical flow components are measured in piezometers near the control well, that is, within a distance, r, in which vertical flow components are significant, that is:5.3 Application of Method to Unconfined Aquifers: 5.3.1 Although the assumptions are applicable to artesian or confined conditions, Weeks (1) has pointed out that the solution may be applied to unconfined aquifers if drawdown is small compared with the saturated thickness of the aquifer or if the drawdown is corrected for reduction in thickness of the aquifer, and the effects of delayed gravity response are small. The effects of gravity response become negligible after a time as given, for piezometers near the water table, by the equation:for values of ar/b < 0.4 and by the equation:for greater values of ar/b.5.3.2 Drawdown in an unconfined aquifer is also affected by curvature of the water table or free surface near the control well, and by the decrease in saturated thickness, that causes the transmissivity to decline toward the control well. This method should be applicable to analysis of tests on water-table aquifers for which the control well is cased to a depth below the pumping level and the drawdown in the control well is less than 0.2b. Moreover, little error would be introduced by effects of water-table curvature, even for a greater drawdown in the control well, if the term (s2/2 b) for a given piezometer is small compared to the δ s term.5.3.3 The transmissivity decreases as a result of decreasing thickness of the unconfined aquifer near the control well. Jacob (4) has shown that the effect of decreasing transmissivity on the drawdown may be corrected by the equation:where s is the observed drawdown and s′ is the drawdown in an equivalent confined aquifer.NOTE 2: The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.1.1 This practice covers an analytical solution for determining the horizontal and vertical hydraulic conductivity of an aquifer by analysis of the response of water levels in the aquifer to the discharge from a well that partially penetrates the aquifer. This standard uses data derived from Test Method D4050.1.2 Limitations—The limitations of the technique for determination of the horizontal and vertical hydraulic conductivity of aquifers are primarily related to the correspondence between the field situation and the simplifying assumption of this practice.1.3 Units—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 nonconformance with the standard. Reporting of test results in units other than SI shall not be regarded as nonconformance with this standard.1.4 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026.1.4.1 The procedures used to specify how data are collected/recorded or calculated, in this standard are regarded as the industry standard. In addition, they are representative of the significant digits that generally should be retained. The procedures used do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user’s objectives; and it is common practice to increase or reduce significant digits of reported data to be commensurate with these considerations. It is beyond the scope of this standard to consider significant digits used in analytical methods for engineering design1.5 This practice offers a set of instructions for performing one or more specific operations. This document cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of the practice may be applicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which the adequacy of a given professional service must be judged, nor should this document be applied without the consideration of a project’s many unique aspects. The word “Standard” in the title of this document means only that the document has been approved through he ASTM consensus process.1.6 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.1.7 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.

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5.1 Test Method D4510 for the counting of partial cleavages, may be used for the acceptance testing of commercial shipments of wool and other animal fibers, but caution is advised, since information on between-laboratory precision is limited. Comparative tests as directed in 5.1.1 may be advisable.5.1.1 In case of a dispute arising from differences in reported test results when using this test method for acceptance testing of commercial shipments, the purchaser and the supplier should conduct comparative tests to determine if there is a statistical bias between their laboratories. Competent statistical assistance is recommended for the investigation of bias. As a minimum, the two parties should take a group of test specimens that are as homogeneous as possible and that are from a lot of material of the type in question. The test specimens should then be randomly assigned in equal numbers to each laboratory for testing. The average results from the two laboratories should be compared using Students t-test for unpaired data and an acceptable probability level chosen by the two parties before the testing is begun. If a bias is found, either its cause must be found and corrected or the purchaser and the supplier must agree to interpret future test results in the light of the known bias.FIG. 1 (A) Partial Cleavage—But do not count if it is at the end of a fiber. The split may have been caused by other means5.2 Chemically damaged or tendered fibers are recognizable microscopically by qualified operators and should not be counted as partial cleavages. Such fibers exhibit total loss of cuticle, severe surface erosion, tenderizing cracks, longitudinal fibrillation, or a combination of these features (see Figs. 1 and 2). In a study of deliberately over-carbonized wool at one laboratory, it was found that when more than 24 tendered fibers were seen in 1 m, partial cleavage counts were significantly higher than on similar fibers that were not overcarbonized.FIG. 1 (B–D) Split Fiber (continued)FIG. 2 Fiber With Transverse Cracks1.1 This test method covers a procedure, using the microprojector, for the counting of partial cleavages in wool and other animal fibers.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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.

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5.1 The presence of partial discharges (corona) at operating voltage in an insulation system has the potential to result in a significant reduction in the life of the insulating material. Some materials are more susceptible to such discharge damage than others. This characteristic can be investigated using Test Method D2275.5.2 The presence of partial discharges (corona) in an apparently solid insulation is a potential indication of the existence of internal cavities. Partial discharge tests have been useful in the design and inspection of molded, laminated, and composite insulation, as well as specimens in the form of cables, capacitors, transformers, bushings, stator bars, and rotating machines (1-9), (13), (12). See also AEIC CS5-87, ICEA T-24-380, IEEE 48, IEEE C57 113-1991, IEEE C57 124-1991, and IEEE 1434-2005.5.3 Partial discharge (corona) inception and extinction voltages are used in the determination of the limiting voltage at which an insulation system will operate free of such discharges. The extinction voltage is often substantially lower than the inception voltage. Where the operating voltage is below the inception voltage but above the extinction voltage, it is possible that a transient over-voltage will initiate discharges which then continue until the voltage is lowered below the extinction voltage. Inception and extinction voltages depend upon many factors, including temperature and the rate at which the voltage is changed. After a time at a voltage, it is possible that discharges will start and stop in a nonuniform and unpredictable fashion, especially for discharges within cavities in certain materials, in particular if the discharge degradation products formed are conductive (1), (5).5.4 The magnitude (pulse height) of a partial discharge is an indication of the amount of energy that it dissipates in the insulation system. Partial discharge magnitude and pulse rate are useful in estimating the rate, or change of rate, at which deterioration is produced.5.5 In general, the occurrence of partial discharges is not directly related to the basic properties of a solid insulating material, but usually results from overstressing of gaseous occlusions or similar imperfections or discontinuities in an insulating system. It is possible that partial discharges will originate at locations such as on the leads or terminals without resulting in any hazard within the main part of the insulation system.1.1 This test method covers the detection and measurement of partial discharge (corona) pulses at the terminals of an insulation system under an applied test voltage, including the determination of partial discharge (corona) inception and extinction voltages as the test voltage is raised and lowered. This test method is also useful in determining quantities such as apparent charge and pulse repetition rate together with such integrated quantities as average current, quadratic rate, and power. This test method is useful for test voltages ranging in frequency from zero (direct voltage) to approximately 2000 Hz.1.2 This test method is directly applicable to a simple insulation system that can be represented as a two-terminal capacitor (1), (2).21.3 This test method is also applicable to (distributed parameter) insulation systems such as high-voltage cable. Consideration must be given to attenuation and reflection phenomena in this type of system. Further information on distributed parameter systems of cables, transformers, and rotating machines will be found in Refs (1-9). (See AEIC CS5-87, IEEE C57 113-1991, IEEE C57 124-1991, and IEEE 1434-2005.)1.4 This test method can be applied to multi-terminal insulation systems, but at some loss in accuracy, especially where the insulation of inductive windings is involved.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. Specific precaution statements are given in Sections 8 and 14.1.6 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.

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5.1 The objective of this practice is to provide guidelines for the preparation of stable, representative, oxidized, relatively unpolluted, aquatic natural-matrix bed-sediment reference test samples. When prepared as described, such test samples should be useful for collaborative methods testing, to evaluate the precision and bias of test methods, and to evaluate test methods performance during their development.5.2 The availability of defined representative natural-matrix reference or test samples, closely approximating a variety of typical environmental samples, is a key requirement for the effective collaborative methods evaluation and development of test methods, and quality assurance testing. When the composition of the reference or test samples has been determined, either for operationally defined “total recoverable” leaching techniques, or for “total analysis” determined by total dissolution, the defined samples should also be suitable for analytical quality assurance testing.5.3 Certified analyses of most rock, sediment, sludge, and soil reference samples are typically based on the total amount of each constituent of interest in the entire sample. “Total” chemical analysis of these samples generally requires complete decomposition or dissolution of the standard material. These are the only feasible analytical approaches if knowledge of finite concentrations for each element of interest in the entire sample is required. Certain instrumental methods, such as X-ray fluorescence or neutron activation analysis, may provide information as to the total constituent composition without sample destruction.5.4 Partial chemical extraction of sediments, or “total recoverable” analyses (operationally defined procedures) for selecting constituents, frequently are useful for defining “available” constituent concentrations. In addition, partial chemical extractions may also provide data on partitioning, phase associations, or on how trace elements are entrained. Operationally defined extractable trace constituent concentrations are generally best obtained by using very specific reagent mixtures and extraction procedures, including method of mixing, vessel size and shape, extraction time, temperature, and so forth.5.5 The various iron and manganese oxides and hydroxides, clay minerals, and organic solutes and particulates, that commonly occur as coatings on most oxidized sediment particles, are generally recognized as the controls governing the concentrations and distribution of most trace metals in natural water-sediment hydrologic environments. Anthropogenic sources clearly dominate in the number of sources and in total loading to most systems, although other factors may also be important.3 Under reducing conditions the iron and manganese oxide coatings, organic components, and associated trace metals may be resolubilized and remobilized. Migration of the reduced solubilized species, with possible subsequent formation of sulfides and so forth, and reoxidation and redeposition at some new location, may then occur. Analysis of extractable trace constituent concentrations in leachates obtained from reduced sediments thus will probably not be indicative of the trace constituent concentrations initially associated with the oxidized and coated sediment grains.1.1 This practice covers uniform procedures to develop, select, collect, prepare, and use oxidized, relatively unpolluted, aquatic natural-matrix bed-sediment reference samples for the collaborative testing of chemical methods of analysis for sediments and similar materials. Reference samples prepared using this practice are intended for use as natural sediments, analyzable for major, minor, and trace elements, and general physical/organic analyses only. The samples are not designed or tested for environmental pollutants such as trace organic compounds.1.2 Few, if any, aquatic sediment reference materials have been certified, defined, or are even available for developing or evaluating partial and sequential extraction procedures. This practice describes factors and considerations in site selection, sample characteristics, collection, and subsequent raw sample treatment needed to prepare natural-matrix bed-material sediments for use as partial or sequential extraction procedure reference test samples. The user of this practice is cautioned that in light of the many variables that may affect natural materials, neither the list of factors included for evaluation nor preparation of natural-matrix reference samples should be considered as all inclusive. It is the user’s responsibility to ensure the validity and applicability of these practices for preparing specific-matrix samples appropriate for testing the constituents of interest and the operationally defined extraction procedures utilized.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.

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4.1 The purpose of this test method is to determine the time citrated plasma exposed to medical materials takes to form a clot when exposed to a suspension of phospholipid particles and calcium chloride. In this test method, the test article is the activator. The PTT assay is a general screening test for a medical material’s ability to activate the intrinsic coagulation pathway. Material samples that show a shortened PTT are activators of the intrinsic coagulation pathway.4.2 The test article, reference materials, and controls are exposed to human plasma. The plasma is tested on a coagulation device. Each sample tube is assayed in duplicate. The results are reported as a percentage of the negative control.1.1 This test method covers the screening of circulating blood-contacting device materials for their ability to induce blood coagulation via the intrinsic coagulation pathway. This assay should be part of the hemocompatibility evaluation for devices and materials contacting human blood, as per ANSI/AAMI/ISO 10993-4.1.2 All safety policies and practices shall be observed during the performance of this test method.1.3 All plasma and any materials that had contact with plasma will be bagged in a biohazard bag, properly labelled with the contents, and disposed of by appropriate means. The plasma should be handled at the Biosafety Level 2 as recommended in the Centers for Disease Control/National Institutes of Health Manual Biosafety in Microbiological Laboratories.1.4 The normal pooled human plasma must have tested negative for Hepatitis B (HBV) or Human Immunodeficiency (HIV) viruses. The plasmas should be treated like any patient plasma using standard precautions. The plasma should be handled at the Biosafety Level 2 as recommended in the Centers for Disease Control/National Institutes of Health Manual Biosafety in Microbiological Laboratories.1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.6 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.1.7 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.

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5.1 The purpose of these tests is to obtain, by means of simple apparatus, reliable and easy to determine values of liquid water transport for capillary active materials expressed in suitable units. These values are for use as part of the material properties in hygrothermal analysis tools for building envelope design and forensic studies. As the topic of liquid transport phenomena in porous materials is very complex, Appendix X1 in ISO 15148 shows some more detailed background information.1.1 This test method defines a procedure to determine the water absorption coefficient of a material by partial submersion. The scope is to evaluate the rate of absorption of water due to capillary forces for building materials in contact with normal or driving rain above grade. The procedure is typically suitable mainly for masonry material, plaster, or a coating in combination with a substrate; but it can also be used for insulation materials. This test method is designed to be used only on homogeneous materials and does not apply to materials that are composites or non-homogeneous (for example, Faced Rigid Closed-cell Insulation). It is not within the scope of this standard to determine liquid uptake phenomena in below-grade applications. The water absorption coefficient is mainly used as an input datum for numerical simulation of the combined heat and moisture transport in building envelopes for design and forensic investigation purposes.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 are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined. However, derived results can be converted from one system to the other using appropriate conversion factors (see Table 1).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.

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5.1 This test method is useful in research and quality control for evaluating insulating materials and systems since they provide for the measurement of the endurance used to compare different materials to the action of corona on the external surfaces. A poor result on this test does not indicate that the material is a poor selection for use at high voltage or at high voltage stress in the absence of surface corona; surface corona is not the same as corona that occurs in internal cavities. (See Test Methods D3382.)5.2 This test method is also useful for comparison between materials of the same relative thickness. When agreed upon between the buyer and the seller, it is acceptable to express any differences in terms of relative time to failure or the magnitude of voltage stress (kV/mm or kV/in.) required to produce failure in a specified number of hours.5.3 It is possible for this test method to also be used to examine the effects of different processing parameters on the same insulating material, such as residual strains produced by quenching, high levels of crystallinity or molding processes that control the concentration and sizes of gas-filled cavities.5.4 The data are generated in the form of a set of values of lifetimes at a voltage. The dispersion of failure times is analyzed using one of the methods below:5.4.1 Weibull Probability Plot.5.4.2 Statistically (see IEEE/IEC 62539-2007 for additional information), to yield an estimate of the central value of the distribution and its standard deviation.5.4.3 Truncating a test at the time of the fifth failure of a set of nine and using that time as the measure of the central tendency. Two such techniques are described in 10.2.5.5 This test method intensifies some of the more commonly met conditions of corona attack so that materials are able to be evaluated in a time that is relatively short compared to the life of the equipment. As with most accelerated life tests, caution is necessary in extrapolation from the indicated life to actual life under various operating conditions in the field.5.6 The possible factors related to failures produced by corona are:5.6.1 Corona eroding the insulation until the remaining insulation can no longer withstand the applied voltage.5.6.2 Corona causing the insulation surface to become conducting due to carbonization, so that failure occurs quickly.5.6.3 Forming of compounds such as oxalic acid crystals causing the surface conductance to vary with ambient humidity. It is possible conductance will be at a sufficient level to reduce the potential gradient at the electrode edge at moderate humidities, and thus cause either a reduction in the amount of corona, or its cessation, thus retarding failure.5.6.4 Corona causing “treeing” within the insulation and consequently accelerating the time to failure.5.6.5 Gases released within the insulation that change its physical dimensions.5.6.6 Changes in the physical properties of an insulating material; embrittlement or cracking, for instance, causing the material to lose flexibility or crack, or both, and thus make it useless.5.7 Tests are often made in open air, at 50 % relative humidity. In cases agreed upon between the buyer and the seller, additional information can be obtained for some materials with tests in circulating air at 20 % relative humidity or less (see Appendix X1).5.7.1 If tests are made in an enclosure, the restriction in the flow of air can trap ozone and influence the results (see Appendix X2).5.7.2 When tests are done outside the standard conditions, the report shall note the deviation and the alternative conditions.5.8 The variability of the time to failure is a function of the consistency of the test parameters, such as voltage levels, which shall be monitored. The Weibull slope factor, β, is recommended as a measure of variability. β is the slope obtained when percent failure is plotted against failure time on Weibull probability paper. Such a plot is called a Weibull Probability Plot (see Fig. 1).FIG. 1 Representative Weibull Plot Showing the First Five Failures of a Group Specimen of Nine.NOTE 1: Plotting percentage are 100 times the average of (n − 1/2 )/N and n/(N + 1). Artificial data were placed on a line (dashed) drawn to illustrate a Weibull line with a β of 4. A second line (not dashed) illustrates the distribution of failure times which are characteristic of materials with very flat volt-time curves, such as mica composites. This line has a β value of 0.7.5.9 The shape of the Weibull Probability Plot can provide additional information. It is possible that a non-straight-line plot will indicate more than one mechanism of failure. For instance, a few unaccountably short time failures in the set indicating a small portion of defective specimens with a different failure mechanism from the rest of the lot.1.1 This test method determines the voltage endurance of solid electrical insulating materials for use at commercial power frequencies under the action of corona (see Note 1). This test method is more meaningful for rating materials with respect to their resistance to prolonged ac stress under corona conditions for comparative evaluation between materials.NOTE 1: The term “corona” is used almost exclusively in this test method instead of “partial discharge,” because it is a visible glow at the edge of the electrode interface that is the result of partial discharge. Corona, as defined in Terminology D1711, is “visible partial discharges in gases adjacent to a conductor.”1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to inch-pound 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. For specific hazard statements, see 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.

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5.1 These test methods are useful in research and quality control for evaluating insulating materials and systems since they provide for the measurement of charge transfer and energy loss due to partial discharges(4) (5) (6).5.2 Pulse measurements of partial discharges indicate the magnitude of individual discharges. However, if there are numerous discharges per cycle it is occasionally important to know their charge sum, since this sum is related to the total volume of internal gas spaces that are discharging, if it is assumed that the gas cavities are simple capacitances in series with the capacitances of the solid dielectrics (7) (8).5.3 Internal (cavity-type) discharges are mainly of the pulse (spark-type) with rapid rise times or the pseudoglow-type with long rise times, depending upon the discharge governing parameters existing within the cavity. If the rise times of the pseudoglow discharges are too long , they will evade detection by pulse detectors as covered in Test Method D1868. However, both the pseudoglow discharges irrespective of the length of their rise time as well as pulseless glow are readily measured either by Method A or B of Test Methods D3382.5.4 Pseudoglow discharges have been observed to occur in air, particularly when a partially conducting surface is involved. It is possible that such partially conducting surfaces will develop with polymers that are exposed to partial discharges for sufficiently long periods to accumulate acidic degradation products. Also in some applications, like turbogenerators, where a low molecular weight gas such as hydrogen is used as a coolant, it is possible that pseudoglow discharges will develop.1.1 These test methods cover two bridge techniques for measuring the energy and integrated charge of pulse and pseudoglow partial discharges:1.2 Test Method A makes use of capacitance and loss characteristics such as measured by the transformer ratio-arm bridge or the high-voltage Schering bridge (Test Methods D150). Test Method A has been found useful to obtain the integrated charge transfer and energy loss due to partial discharges in a dielectric from the measured increase in capacitance and tan δ with voltage. (See also IEEE 286 and IEEE 1434)1.3 Test Method B makes use of a somewhat different bridge circuit, identified as a charge-voltage-trace (parallelogram) technique, which indicates directly on an oscilloscope the integrated charge transfer and the magnitude of the energy loss due to partial discharges.1.4 Both test methods are intended to supplement the measurement and detection of pulse-type partial discharges as covered by Test Method D1868, by measuring the sum of both pulse and pseudoglow discharges per cycle in terms of their charge and energy.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. Specific precaution statements are given in Section 7.1.6 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.

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AS 1018-1985 Partial discharge measurements 现行 发布日期 :  1970-01-01 实施日期 : 

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