1.1 This specification covers the recommended design requirements and manufacturing practices for monolithic or sectional precast concrete water and wastewater structures with the exception of concrete pipe, box culverts, utility structures, septic tanks, grease interceptor tanks, and items included under the scope of Specification C478/C478M.NOTE 1: Water and wastewater structures are defined as solar heating reservoirs, cisterns, holding tanks, leaching tanks, extended aeration tanks, wet wells, pumping stations, distribution boxes, oil-water separators, treatment plants, manure pits, catch basins, drop inlets, and similar structures.NOTE 2: Installation and sealant requirements should receive special consideration due to special features of the application.1.2 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.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 AE examination is useful to detect micro-damage generation, accumulation, and growth of new or existing flaws. The examination is also used to detect significant existing damage from friction-based AE generated during loading or unloading of these regions. The damage mechanisms that can be detected include matrix cracking, fiber splitting, fiber breakage, fiber pull-out, debonding, and delamination. During loading, unloading, and load holding, damage that does not emit AE energy will not be detected.5.2 When the detected signals from AE sources are sufficiently spaced in time so as not to be classified as continuous AE, this practice is useful to locate the region(s) of the 2-D test sample where these sources originated and the accumulation of these sources with changing load or time, or both.5.3 The probability of detection of the potential AE sources depends on the nature of the damage mechanisms, flaw characteristics, and other aspects. For additional information, see X1.4.5.4 Concentrated damage in fiber/polymer composites can lead to premature failure of the composite item. Hence, the use of AE to detect and locate such damage is particularly important.5.5 AE-detected flaws or damage concentrated in a certain region may be further characterized by other NDE techniques (for example, visual, ultrasonic, etc.) and may be repaired as appropriate. Repair procedure recommendations and the subsequent examination of the repair are outside the scope of this practice. For additional information, see X1.5.5.6 This practice does not address sandwich core, foam core, or honeycomb core plate-like composites due to the fact that currently there is little in the way of published work on the subject resulting in a lack of a sufficient knowledge base.5.7 Refer to Guide E2533 for additional information about types of defects detected by AE, general overview of AE as applied to polymer matrix composites, discussion of the Felicity ratio (FR) and Kaiser effect, advantages and limitations, AE of composite parts other than flat panels, and safety hazards.1.1 This practice covers acoustic emission (AE) examination or monitoring of panel and plate-like composite structures made entirely of fiber/polymer composites.1.2 The AE examination detects emission sources and locates the region(s) within the composite structure where the emission originated. When properly developed AE-based criteria for the composite item are in place, the AE data can be used for nondestructive examination (NDE), characterization of proof testing, documentation of quality control, or for decisions relative to structural-test termination prior to completion of a planned test. Other NDE methods may be used to provide additional information about located damage regions. For additional information, see X1.1 in Appendix X1.1.3 This practice can be applied to aerospace composite panels and plate-like elements as a part of incoming inspection, during manufacturing, after assembly, continuously (during structural health monitoring), and at periodic intervals during the life of a structure.1.4 This practice is meant for fiber orientations that include cross-plies, angle-ply laminates, or two-dimensional woven fabrics. This practice also applies to 3-D reinforcement (for example, stitched, z-pinned) when the fiber content in the third direction is less than 5 % (based on the whole composite).1.5 This practice is directed toward composite materials that typically contain continuous high modulus greater than 20 GPa [3 Msi] fibers.1.6 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 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.1.7 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.1.8 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 used to estimate and categorize the number and type of fungal structures present on an inertial impactor sample.5.2 Fungal structures are identified and quantified regardless of whether they would or would not grow in culture.5.3 It must be emphasized that the detector in this test method is the analyst, and therefore results are subjective, depending on the experience, training, qualification, and mental and optical fatigue of the analyst.1.1 This test method is a procedure that uses direct microscopy to analyze the deposit on an inertial impaction sample.1.2 This test method describes procedures for categorizing and enumerating fungal structures by morphological type. Typically, categories may be as small as genus (for example, Cladosporium) or as large as phylum (for example, basidiospores).1.3 This test method contains two procedures for enumerating fungal structures: one for slit impaction samples and one for circular impaction samples. This test method is applicable for impaction air samples, for which a known volume of air (at a rate as recommended by the manufacturer) has been drawn, and is also applicable for blank impaction samples.1.4 Enumeration results are presented in fungal structures/sample (fs/sample) and fungal structures/m3 (fs/m3).1.5 The range of enumeration results that can be determined with this test method depends on the size of the spores on the sample trace, the amount of particulate matter on the sample trace, the percentage of the sample trace counted, and the volume of air sampled.1.6 This test method addresses only the analysis of samples. The sampling process and interpretation of results is outside the scope of this test method.1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.8 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.1.9 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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1.1 This specification covers the airworthiness requirements that address the interaction of systems and structures. The material was developed through open consensus of international experts in general aviation. This information was created by focusing on Normal Category aeroplanes. The content may be more broadly applicable; it is the responsibility of the applicant to substantiate broader applicability as a specific means of compliance.1.2 An applicant intending to propose this information as Means of Compliance for a design approval must seek guidance from their respective oversight authority (for example, published guidance from applicable Civil Aviation Authority (CAAs)) concerning the acceptable use and application thereof. For information on which oversight authorities have accepted this specification (in whole or in part) as an acceptable Means of Compliance to their regulatory requirements (hereinafter “the Rules”), refer to the ASTM Committee F44 web page (www.ASTM.org/COMMITTEE/F44.htm). Annex A1 maps the Means of Compliance of the ASTM Standards to EASA CS-23, amendment 5, or later, and FAA 14 CFR Part 23, amendment 64, or later.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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定价： 515元 / 折扣价： 438 元 加购物车

定价： 590元 / 折扣价： 502 元 加购物车

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5.1 This standard provides measurement procedures for determining the electromagnetic shielding effectiveness of durable rigid wall relocatable shielded enclosures. This standard specifies a method for comparing the shielded enclosure performance of structures provided by different suppliers. In addition, this standard is written to minimize variations in measured shielding effectiveness at a given frequency and test point regardless of test personnel, equipment, and test site. Therefore, the shielding effectiveness of a durable rigid wall relocatable shielded enclosure of any size from any supplier can be determined. This standard specifies a minimum set of measurements at a given frequency and a minimum set of frequencies to determine shielding effectiveness.5.2 Source Fields—Performance of a shielded enclosure is to be assessed for two source fields: magnetic and plane wave.5.2.1 Magnetic Field Measurements—The attenuation provided by a shielded enclosure is assessed by using a local source to generate the near field. The magnetic field measurements are specified for two narrow frequency bands: 140 kHz to 160 kHz and 14 MHz to 16 MHz.5.2.2 Plane Wave Measurements—The attenuation provided by a shielded enclosure is assessed by using a locally generated distant source or plane wave field. The plane wave measurements are specified for three narrow frequency bands: 300 MHz to 500 MHz, 900 MHz to 1000 MHz, and 8.5 GHz to 10.5 GHz.1.1 This test method covers the determination of the electromagnetic shielding effectiveness of durable relocatable shielded enclosures.1.1.1 The intended application of this test method is for virgin shielded enclosures that do not have any equipment or equipment racks. It is recommended that tests be conducted before the interior finish work begins. However, the shield assembly including all enclosure penetrations shall be completed and required penetration protection devices shall be installed in accordance with the design specification. The test method can also be used on existing shielded enclosures after repair work is done to verify workmanship, but it may be necessary to remove equipment or equipment racks to gain access to a test area.1.1.2 The test procedures delineated in this document are comprehensive and may require several days to complete for a room-size shielded enclosure. A user can apply this test method for a first article test that requires proof of concept and validation of design and fabrication technique. Appendix X2 provides guidance on choosing test points so shielding effectiveness tests on a room-size shielded enclosure may be completed in about one-half day for which it applies to shielded enclosures coming off an assembly line.1.2 This test method is for use in the following frequency ranges: 140 kHz to 160 kHz, 14 MHz to 16 MHz, 300 MHz to 500 MHz, 900 MHz to 1000 MHz, and 8.5 GHz to 10.5 GHz. Specific test frequencies within these ranges are required (see 11.1.1 and 11.2.1). Additional measurements in the range of 10 kHz to 10.5 GHz may be performed. For specific applications, the frequency range may be extended from 50 Hz to 40 GHz. Appendix X1 provides guidance on selecting measurement frequencies.1.3 This test method is not applicable to individual components such as separate walls, floors, ceilings, or shielded racks.1.4 This standard may involve hazardous materials, operations, equipment, or any combination.1.5 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units 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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