定价： 1358元

定价： 462元

定价： 640元

定价： 529元

定价： 1054元

1.1 This test method covers the determination of free formaldehyde in amino resins and their aqueous and nonaqueous solutions. Amino resin-free formaldehyde levels from about 0.02 to 5.0% can be determined by this test method. The applicability of this test method to other matrices is unknown. 1.2 This standard does not purport to address the safety problems associated with its use. It is the responsibility of the user of this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

定价： 0元

1.1 This specification covers seven types of free-cutting copper rod and bar as follows: Copper or Copper Alloy UNS No. 2 Type C14500 copper-tellurium C14510 copper-tellurium C14520 copper-tellurium C14700 copper-sulfur C18700 copper-lead

定价： 0元

5.1 The data from this test can be used to determine the superficial gas velocity required to suspend a bed of powder in the fluidized state and the resulting pressure drop.Note 4—The quality of the results 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 ensure reliable results. Reliable results depend on many factors: Practice D3740 provides a means of evaluating some of those factors.Practice D3740 was developed for agencies engaged in the testing or inspection or both of soil and rock. As such it is not totally applicable to agencies performing this standard. However, users of this standard should recognize that the framework of Practice D3740 is appropriate for evaluating the quality of an agency performing this standard. Currently there is no known qualifying national authority that inspects agencies that perform this standard.1.1 This test method describes the apparatus and procedure needed for determining the minimum fluidization velocity of Geldart Group A powders and the minimum fluidization or complete fluidization velocity of Geldart Group B powders.1.1.1 This test method is for powders that are readily or easily fluidizable and fall into the category of Group A and B of the “Geldart” classification. The fluidization of Geldart Group C powders will be addressed in another standard. This test method could apply to Geldart Group D particles but the focus of this document is towards Group and A and B materials.1.1.2 Geldart classification of powders is often defined by comparing the Sauter mean particle size with the difference between the particle density and the density of the fluidizing gas, as illustrated in Fig. 1 (1).2FIG. 1 Geldart Classification of Particles1.1.2.1 Group A powders are easily fluidized but there is a difference between the gas velocity where the bed is initially fluidized and the velocity where bubbles are first observed. For Group A powders, bed expansion can be considerable before any bubbles are observed. Group B powders are also easily fluidized; but there is no difference between the velocity where the bed is fluidized and the velocity at the onset of bubbling. The minimum gas velocity, where all of the particles are fully supported by the gas for Group B powders, is often referred to as the “complete fluidization velocity” instead of minimum fluidization velocity. Group C powders are cohesive and can be difficult to fluidize.1.1.2.2 Group A powders can be distinguished from Group B powders by the response to deaeration. Group A powders deaerate relatively slowly whereas Group B powders deaerate almost instantaneously in fluidized beds.1.1.2.3 Group A Powders that lie near or on the Group A/C boundary may be tested by this method. However, if the powders do not fluidize freely, test results should be considered invalid.1.1.2.4 Temperature, moisture (water) content, particle size distribution, particle shape and sometimes other variables influence the Geldart classification of a powder. Deaeration testing specified in 1.1.2.2 is a more definitive test than simply using particle size and density differences as described in 1.1.2.Note 1—A Standard Practice for deaeration testing is under development.1.2 This test method should be performed in a laboratory under controlled conditions of temperature and humidity.1.3 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026.1.3.1 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 variations, the 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 analysis methods for engineering design.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 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.

定价： 0元

1.1 Particle size, shape, and bulk density will affect the flowability of powder material. This test method is used for the determination of the angle of repose of free-flowing mold powders. At angles greater than this value this material will flow.1.2 The values stated in inch-pound units and degrees are to be regarded as standard. The values stated in parentheses are for information only.1.3This 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.

定价： 0元

1.1 This specification covers free-cutting brass rod, bar, wire and shapes of any specified cross section suitable for high-speed screw machine work. The material is Copper Alloy UNS No. C36000. 1.2 Most rods made to this specification are furnished as straight lengths. However, sizes 12 mm and under may be furnished in coil form when requested. Note 1-This specification is the metric companion to Specification B16.

定价： 0元

1.1 These test methods cover the determination of the amount of apparent free phenol in synthetic phenolic resins or solutions used for coating purposes. The test method for isolation of the free phenol applies to all the commonly used resins except those containing p-phenyl-phenol. Test Method A applies to the simpler phenols up to and including the xylenols; Test Method B applies to the common alkylated phenols. >1.2 This standard does not purport to address all of the safety problems, 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. >

定价： 0元

定价： 551元

定价： 775元

定价： 271元

定价： 329元