定价： 590元 加购物车

定价： 515元 加购物车

定价： 515元 加购物车

5.1 These test methods are useful adjunct to dynamic thermal tests that are performed under conditions in which the sample temperature is increased continuously at a programmed rate. Results obtained under dynamic test conditions present difficulties in determining the temperature at which an exotherm initiates because onset temperature is dependent on heating rate. These test methods describe in the present standard attempts to determine the onset temperature under isothermal conditions where the heating rate is zero.1.1 These test methods describe the assessment of constant-temperature stability (CTS) of chemical materials that undergo exothermic reactions. The techniques and apparatus described may be used on solids, liquids, or slurries of chemical substances.1.2 When a series of materials is tested by these test methods, the results permit ordering the materials relative to each other with respect to their thermal stability.1.3 Limitations of Test: 1.3.1 These test methods are limited to ambient temperatures and above.1.3.2 These test methods determine neither a safe storage temperature nor a safe processing temperature.NOTE 1: A safe storage or processing temperature requires that any heat produced by a reaction be removed as fast as generated and that proper consideration be given to hazards associated with reaction products.1.3.3 When these test methods are used to order the relative thermal stability of materials, the tests must be run under the same confinement condition (see 8.3).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 should be used to measure and describe the properties of materials, products, or assemblies in response to heat and flame under controlled laboratory conditions and should not be used to describe or appraise the fire hazard or fire risk of materials, products, or assemblies under actual fire conditions. However, results of this test may be used as elements of a fire risk assessment which takes into account all of the factors which are pertinent to an assessment of the fire hazard of a particular end use.1.6 This standard may involve hazardous materials, operations, and equipment. 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 This test method is useful in detecting potentially hazardous reactions including those from volatile chemicals and in estimating the temperatures at which these reactions occur and their enthalpies (heats). This test method is recommended as an early test for detecting the thermal hazards of an uncharacterized chemical substance or mixture (see Section 8).5.2 The magnitude of the change of enthalpy may not necessarily denote the relative hazard in a particular application. For example, certain exothermic reactions are often accompanied by gas evolution that increases the potential hazard. Alternatively, the extent of energy release for certain exothermic reactions may differ widely with the extent of confinement of volatile products. Thus, the presence of an exotherm and its approximate temperature are the most significant criteria in this test method (see Section 3 and Fig. 1).5.3 When volatile substances are being studied, it is important to perform this test with a confining pressurized atmosphere so that changes of enthalpy that can occur above normal boiling or sublimation points may be detected. As an example, an absolute pressure of 1.14 MPa (150 psig) will generally elevate the boiling point of a volatile organic substance 100 °C. Under these conditions exothermic decomposition is often observed.5.4 For some substances the rate of enthalpy change during an exothermic reaction may be small at normal atmospheric pressure, making an assessment of the temperature of instability difficult. Generally, a repeated analysis at an elevated pressure will improve the assessment by increasing the rate of change of enthalpy.NOTE 1: The choice of pressure may sometimes be estimated by the pressure of the application to which the material is exposed.5.5 The four significant criteria of this test method are: the detection of a change of enthalpy; the approximate temperature at which the event occurs; the estimation of its enthalpy and the observance of effects due to the cell atmosphere and pressure.1.1 This test method describes the ascertainment of the presence of enthalpic changes in a test specimen, using minimum quantities of material, approximates the temperature at which these enthalpic changes occur and determines their enthalpies (heats) using differential scanning calorimetry or pressure differential scanning calorimetry.1.2 This test method may be performed on solids, liquids, or slurries.1.3 This test method may be performed in an inert or a reactive atmosphere with an absolute pressure range from 100 Pa through 7 MPa and over a temperature range from 300 K to 800 K (27 °C to 527 °C).1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4.1 Exceptions—Inch-pound units are provided as a courtesy to the user in 5.3, 7.2.2.1, 7.2.2.2, and 11.4.1.5 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 safety precautions are given in Section 8.1.6 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 This test method provides an indication of thermal oxidative stability of distillate fuels when heated to high temperatures that simulate those that may occur in some types of recirculating engine or burner fuel delivery systems. Results have not been substantially correlated to engine or burner operation. The test method can be useful for investigation of operational problems related to fuel thermal stability.5.2 When the test method is used to monitor manufacture or storage of fuels, changes in filter rating values can indicate a relative change in inherent stability. Storage stability predictions are more reliable when correlated to longer-term storage tests, for example, Test Method D4625, or other lower temperature, long-term tests. When fuel samples are freshly produced, aging for 180 min, instead of the traditional 90 min interval, tends to give a result correlating more satisfactorily with the above methods (see Appendix X2).5.3 The test method uses a filter paper with a nominal porosity of 11 μm, which will not capture all of the sediment formed during aging but allows differentiation over a broad range. Reflectance ratings are also affected by the color of filterable insolubles, which may not correlate to the mass of the material filtered from the aged fuel sample. Therefore, no quantitative relationship exists between the pad rating and the gravimetric mass of filterable insolubles.1.1 This test method covers relative stability of middle distillate fuels under high temperature aging conditions with limited air exposure. This test method is suitable for all No. 1 and No. 2 grades in Specifications D396, D975, D2880, and D3699. It is also suitable for similar fuels meeting other specifications.1.2 This test method is not suitable for fuels whose flash point, as determined by Test Methods D56, D93, or D3828, is less than 38 °C. This test method is not suitable for fuels containing residual oil.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3.1 Exception—The maximum vacuum includes inch-pound units in 6.5 and 11.2.1.4 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 加购物车

5.1 Heat transfer fluids degrade when exposed to sufficiently high temperatures. The amount of degradation increases as the temperature increases or the length of exposure increases, or both. Due to reactions and rearrangement, degradation products can be formed. Degradation products include high and low boiling components, gaseous decomposition products, and products that cannot be evaporated. The type and content of degradation products produced will change the performance characteristics of a heat transfer fluid. In order to evaluate thermal stability, it is necessary to quantitatively determine the mass percentages of high and low boiling components, as well as gaseous decomposition products and those that cannot be vaporized, in the thermally stressed heat transfer fluid.5.2 This test method differentiates the relative stability of organic heat transfer fluids at elevated temperatures in the absence of oxygen and water under the conditions of the test.5.3 The user shall determine to his own satisfaction whether the results of this test method correlate to field performance. Heat transfer fluids in industrial plants are exposed to a variety of additional influencing variables. Interaction with the plant's materials, impurities, heat build-up during impaired flow conditions, the temperature distribution in the heat transfer fluid circuit, and other factors can also lead to changes in the heat transfer fluid. The test method provides an indication of the relative thermal stability of a heat transfer fluid, and can be considered as one factor in the decision-making process for selection of a fluid.5.4 The accuracy of the results depends very strongly on how closely the test conditions are followed.5.5 This test method does not possess the capability to quantify or otherwise assess the formation and nature of thermal decomposition products within the unstressed fluid boiling range. Decomposition products within the unstressed fluid boiling range may represent a significant portion of the total thermal degradation.1.1 This test method covers the determination of the thermal stability of unused organic heat transfer fluids. The procedure is applicable to fluids used for the transfer of heat at temperatures both above and below their boiling point (refers to normal boiling point throughout the text unless otherwise stated). It is applicable to fluids with maximum bulk operating temperature between 260 °C (500 °F) and 454 °C (850 °F). The procedure shall not be used to test a fluid above its critical temperature. In this test method, the volatile decomposition products are in continuous contact with the fluid during the test. This test method will not measure the thermal stability threshold (the temperature at which volatile oil fragments begin to form), but instead will indicate bulk fragmentation occurring for a specified temperature and testing period. Because potential decomposition and generation of high pressure gas may occur at temperatures above 260 °C (500 °F), do not use this test method for aqueous fluids or other fluids which generate high-pressure gas at these temperatures.1.2 DIN Norm 51528 and GB/T 23800 cover other test methods that are similar to this test method.1.3 The applicability of this test method to siloxane-based heat transfer fluids has not been determined.1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses are 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. For specific warning statements, see 7.2, 8.8, 8.9, and 8.10.1.6 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 This test method provides information on the stability of the engine coolant concentrate when stored at elevated temperatures for two weeks. These test conditions might simulate the conditions that a product would be subjected to in transit and storage in warehouses before delivery to the customer.4.2 This test method provides information on the stability of an engine coolant diluted with synthetic hard water at elevated temperatures. This test method provides a laboratory method to test the sensitivity of the engine coolant to hard water.1.1 This test method covers a simple glassware-type procedure for evaluating the effects of temperature and hard water on the stability of engine coolants at elevated temperatures under controlled laboratory conditions.1.2 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.1.3 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 加购物车

5.1 This test method is intended for use on all types of finished leathers.5.2 Finish stability is a significant factor in establishing the application and function of leather.1.1 This test method covers the determination of resistance of leather finish to cracking, flaking or becoming tacky after aging.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.

定价： 515元 加购物车

定价： 590元 加购物车

定价： 515元 加购物车

定价： 590元 加购物车

定价： 590元 加购物车

定价： 590元 加购物车

定价： 590元 加购物车