定价： 1665元 / 折扣价： 1482 元 加购物车

定价： 1290元 / 折扣价： 1149 元 加购物车

定价： 2081元 / 折扣价： 1853 元 加购物车

定价： 283元 / 折扣价： 252 元 加购物车

定价： 1290元 / 折扣价： 1149 元 加购物车

定价： 1665元 / 折扣价： 1482 元 加购物车

定价： 2081元 / 折扣价： 1853 元 加购物车

定价： 1665元 / 折扣价： 1482 元 加购物车

定价： 1290元 / 折扣价： 1149 元 加购物车

定价： 2081元 / 折扣价： 1853 元 加购物车

定价： 1290元 / 折扣价： 1149 元 加购物车

定价： 590元 加购物车

4.1 Tests conducted in accordance with this practice are used to evaluate the stability of plastic materials when they are exposed outdoors. The relative durability of plastics in outdoor use can be very different depending on the location of the exposure because of differences in ultraviolet (UV) radiation, time of wetness, temperature, pollutants, and other factors. It cannot be assumed, therefore, that results from one exposure in a single location will be useful for determining relative durability in a different location. Exposures in several locations with different climates that represent a broad range of anticipated service conditions are recommended.4.1.1 Because of year-to-year climatological variations, results from a single exposure test cannot be used to predict the absolute rate at which a material degrades. Several years of repeat exposures are needed to get an average test result for a given location.4.2 The results of short-term exposure tests can provide an indication of relative outdoor performance, but it is recommended they not be used to predict the absolute long-term performance of a material. The results of tests conducted for less than twelve months will depend on the particular season of the year in which they begin.1.1 This practice is intended to cover procedures for the exposure of plastic materials to weather.NOTE 1: See Practice G24 for aging under glass.1.2 This practice is limited to the method by which the material is to be exposed and the general procedure to be followed. It is intended for use with finished articles of commerce as well as with all sizes and shapes of test specimens.1.3 Means of evaluation of the effects of weathering will depend on the intended use for the test material.1.4 The values stated in SI units are to be regarded as the 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.NOTE 2: This standard and ISO 877.2-2009, Method A, are technically equivalent.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 加购物车

4.1 Since coated pipe may be stored outdoors for long periods before burial, weathering tests described in this practice are needed to evaluate the stability of these coatings stored outdoors. The results obtained should be treated only as indicating the general effect of weathering. Exposure conditions vary greatly from year to year, from one part of a year to another, and from locality to locality. The results of short-term exposure tests in the north are more meaningful if exposure is started in the summer followed by a winter season. In southern areas where climatic conditions are more uniform throughout the year, the time of year when short-term exposure is started is less critical. In all localities, the longer the exposure period, the more reliable are the results obtained.1.1 This practice is intended to define conditions for the exposure of coated metal pipe to weather.1.2 This practice specifies qualifications for the samples, procedure to be followed in exposure to weather, and procedure for evaluating effects of exposure including visual examination and other tests.1.3 The values stated in SI units to three significant decimals are to be regarded as the standard. The values given in parentheses are for information only.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： 515元 加购物车

4.1 Tests conducted in accordance with this practice are used to evaluate the weatherability of construction seals and sealant materials when they are exposed to outdoor weather conditions. The weatherability of seals and sealants in actual outdoor use can be very different depending on the location because of differences in solar radiation, moisture, temperature, pollutants, and other factors. Sealant color may also affect weatherability.4.2 This practice allows for three options: Option 1 – Procedure A in which the effect of movement during weathering is not considered; Option 2 – Procedure B in which specimens are weathered in conjunction with movement based on thermal changes. The applied strain is proportional to a combination of the temperature at the time the equipment is set up and subsequent thermal changes. This option closely mimics the actual movements that occur in many sealant installations, but is less repeatable than the movement in Procedure C; Option 3 – Procedure C in which the strain during weathering is manually applied. This procedure allows for excellent control and repeatability, but is less representative of movement in actual use conditions than the movement in Procedure B. Options 2 and 3 have been added to this practice based on peer reviewed scientific literature demonstrating that applied strain separately and in combination with other weathering stresses causes changes in the weatherability of sealants.4.3 The type, frequency and amount of movement of sealants varies with location and may affect weatherability. It cannot be assumed, therefore, that results from one exposure in a single location will be useful for determining weatherability in a different location. Exposures in several locations with different climates (for example, solar radiation, moisture, temperature, pollutants, biological and other factors) that represent a broad range of anticipated service conditions are recommended.4.4 It is strongly recommended that control materials of similar composition and construction to the test specimens and with known weatherability be exposed along with the test specimens for the purpose of comparing the performance of test materials to the controls. (See 6.2).4.5 The results of short-term exposure tests can provide an indication of relative outdoor performance, but they shall not be used to predict the absolute long-term performance of a seal or sealant material. The results of tests conducted for less than 12 months will depend on the particular season of the year in which they begin.4.6 Because of year-to-year climatatological variations, results from a single exposure test cannot be used to predict the absolute rate at which a seal or sealant degrades. Several years of repeat exposures are needed to determine an average test result for a given location.4.7 Climatic and construction factors can impose cyclic movement upon sealed joints in use. This movement can impact the effects of outdoor weathering and often causes types of failure that are not produced by weathering without movement. Thus, the ability of building joint sealants to withstand temperature-induced movements of compression and expansion is an important property.4.8 Outdoor weathering of specimens in combination with natural or forced cyclic movement during exposure can provide a more realistic assessment of the ability of a seal or sealant to withstand the combined effects of climate and movement encountered by seals and sealants in building construction applications.1.1 This practice describes outdoor exposure procedures to be used as part of a test designed to determine the weatherability of building construction, seals and sealants.NOTE 1: See Practice G24 for Exposures to Daylight Filtered Through Glass.1.2 This practice includes three procedures for outdoor weathering. Procedure A exposes specimens to outdoor weathering without movement. Procedure B and Procedure C are, respectively, continuous natural and periodic manual techniques for subjecting specimens to the combination of cyclic movement and exposure to outdoor weathering.1.3 This practice is limited to the method by which the construction seals or sealants are exposed to outdoor weathering as part of a test program. It refers to the types of evaluations to be performed following the outdoor exposure but does not describe the test methods.1.4 Means of evaluation of the effects of weathering will depend on the intended use of the test material.1.5 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.1.6 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.

定价： 590元 加购物车