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定价： 530元

1.1 This test method covers equipment and techniques for determining porosity in gold coatings, particularly electrodeposits and clad metals used on electrical contacts. 1.2 This test method is designed to show whether the porosity level is less or greater than some value which by experience is considered by the user to be acceptable for the intended application. 1.3 This test method is suitable for flat surfaces, or with appropriate fixtures, for gently curved surfaces. 1.4 A variety of other porosity testing methods are described in Guide B765 and in the literature. Detailed critical reviews of porosity testing are also available. Other porosity test methods are B735, B798, B799 and B809. 1.5 This test method is specifically designed for use with gold coatings (>95% gold) on substrates of copper and nickel and their alloys. Although not covered in this standard, variations of this test method may be found useful in evaluating coatings other than gold. 1.6 The values stated in SI units are to be regarded as standard. The values in parenthesis are for information only. 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 and health practices and determine the applicability of regulatory limitations prior to its use. For a specific precautionary statement, see Note 1.

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This test method provides no absolute information, rather ranking only of the selected series of paints.This test method can provide a pass-fail situation if known acceptable and unacceptable paints are included in the test.1.1 This test method covers the determination of the comparative coalescence of a series of latex paints by determining the porosity of films dried at standard and at low temperature. Porosity is evaluated with a penetrating medium as in Test Method D 3258.1.2 The texture of the film, which can affect cleanup, will influence the results of the test. Stain applied to a high-hiding paint will not lower the reflectance as much as the same stain applied to a low-hiding paint of equal porosity. These points must be considered in comparing the different paints.1.3 This method should be used only for comparative testing within one laboratory, as the numerical results obtained by different laboratories do not usually agree.1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.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.

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1.1 This test method describes a procedure for measuring the interior pore volume and the apparent pore diameter distribution of porous poly(vinyl chloride) resins. The measurements are made by forcing mercury under increasing pressure through a graduated penetrometer into the open pores of the resin samples. The volume of mercury forced into the pores is defined from the change of the mercury volume in the penetrometer; the apparent pore diameter distribution can be defined from incremental volume changes with increasing pressure. 1.2 Warning-This standard includes the use of an OSHA-designated hazardous chemical (Mercury). For specific hazard information and guidance relative to use, consult the health and safety documents provided by the supplier, for example, the material safety data sheet. 1.3 The values stated in inch-pound units 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 and health practices and determine the applicability of regulatory limitations prior to use. Note 1-There are no ISO standards covering the primary subject matter of this test method.

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The volume of an arbitrary P/M shape cannot be accurately measured by standard techniques such as by micrometers or calipers. Since density is mass/volume, a precise method to measure the volume is needed. For nonporous objects, the volume of water displaced by the immersed object is determined by Archimedes principle. For porous P/M parts, a method is required to seal surface connected pores. If the pores are not sealed or the part is not oil impregnated, the part will absorb some of the water and decrease its buoyancy and exhibit an erroneously high density.Density and oil content values are generally contained in the specifications for oil-impregnated bearings and other self-lubricating P/M parts. Desired lubrication requires sufficient interconnected porosity and satisfactory oil impregnation of the porosity.For a particular P/M material, the mechanical properties of P/M structural parts are directly related to their density. Density values are therefore generally contained in the specifications for P/M parts.1.1 This test method covers determination of the density, oil content, and interconnected porosity of sintered bearings and structural parts with or without oil impregnation.1.2 The values stated in SI units are to be regarded as the standard. The values 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 and health practices and determine the applicability of regulatory limitations prior to use.

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