4.1 These test methods measure the approximate surface area of precipitated hydrated silicas that is available to the nitrogen molecule using an approximation of the B.E.T. method. While the multi-point version of the B.E.T. method is generally accepted as being less prone to errors arising from the varying surface properties of individual samples, the single-point approximation is often adequate due to the shorter time per test and relative simplicity of the instrumentation needed. Quality control applications and comparative tests on near-identical samples of close chemical and micro-structural composition are likely to be the applications of greatest value.1.1 These test methods cover a procedure to measure the surface area of precipitated hydrated silicas by, a single point approximation of the Brunauer, Emmett, and Teller (B.E.T.)2 theory of multilayer gas adsorption. These test methods specify the sample preparation and treatment, instrument calibrations, required accuracy and precision of experimental data, and calculations of the surface area results from the obtained data.1.2 These test methods are used to determine the single point nitrogen surface areas in the range of 100 to 500 m2/g.1.3 The values stated in SI units are to be regarded as the standard. The values 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. The minimum safety equipment should include protective gloves, sturdy eye and face protection.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.

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4.1 The iodine adsorption number is useful in characterizing carbon blacks. It is related to the surface area of carbon blacks and is generally in agreement with nitrogen surface area. The presence of volatiles, surface porosity, or extractables will influence the iodine adsorption number. Aging of carbon black can also influence the iodine number.1.1 This test method covers the determination of the iodine adsorption number of carbon black.1.1.1 Method A is the original test method for this determination and Method B is an alternate test method using automated sample processing and analysis.1.2 The iodine adsorption number of carbon black has been shown to decrease with sample aging. Iodine Number reference materials have been produced that exhibit stable iodine number upon aging. One or more of these reference materials are recommended for daily monitoring (x-charts) to ensure that the results are within the control limits of the individual reference material. Use all Iodine Number reference materials from a set for standardization of iodine testing (see Section 8) when target values cannot be obtained.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 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.

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5.1 Advanced ceramic powders and porous ceramic bodies often have a very fine particulate morphology and structure that are marked by high surface-to-volume (S-V) ratios. These ceramics with high S-V ratios commonly exhibit enhanced chemical reactivity and lower sintering temperatures. Results of many intermediate and final ceramic processing steps are controlled by, or related to, the specific surface area of the advanced ceramic. The functionality of ceramic adsorbents, separation filters and membranes, catalysts, chromatographic carriers, coatings, and pigments often depends on the amount and distribution of the porosity and its resulting effect on the specific surface area.5.2 This test method determines the specific surface area of advanced ceramic powders and porous bodies. Both suppliers and users of advanced ceramics can use knowledge of the surface area of these ceramics for material development and comparison, product characterization, design data, quality control, and engineering/ production specifications.1.1 This test method covers the determination of the surface area of advanced ceramic materials (in a solid form) based on multilayer physisorption of gas in accordance with the method of Brunauer, Emmett, and Teller (BET) (1)2 and based on IUPAC Recommendations (1984 and 1994) (2, 3). This test method specifies general procedures that are applicable to many commercial physical adsorption instruments. This test method provides specific sample outgassing procedures for selected common ceramic materials, including: amorphous and crystalline silicas, TiO2, kaolin, silicon nitride, silicon carbide, zirconium oxide, etc. The multipoint BET (1) equation along with the single-point approximation of the BET equation are the basis for all calculations. This test method is appropriate for measuring surface areas of advanced ceramic powders down to at least 0.05 m2  (if in addition to nitrogen, krypton at 77.35 K is utilized as an adsorptive).1.2 This test method does not include all existing procedures appropriate for outgassing of advanced ceramic materials. However, it provides a comprehensive summary of procedures recommended in the literature for selected types of ceramic materials. The investigator shall determine the appropriateness of listed procedures.1.3 The values stated in SI units are to be regarded as standard. State all numerical values in terms of SI units unless specific instrumentation software reports surface area using alternate units. In this case, provide both reported and equivalent SI units in the final written report. It is commonly accepted and customary (in physical adsorption and related fields) to report the (specific) surface area of solids as m2/g and, as a convention, many instruments (as well as certificates of reference materials) report surface area as m2 g–1, instead of using SI units (m2 kg–1).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.

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5.1 This test method is useful for determining the specific surface area of catalysts and catalyst carriers for material specifications, manufacturing control, and research and development in the evaluation of catalysts.1.1 This test method covers the single-point determination of the surface area of catalysts and catalyst carriers that exhibit Type II or Type IV nitrogen adsorption isotherms using a nitrogen-helium flowing gas mixture. This test method is applicable for the determination of total surface areas from 0.1 to 300 m2, where rapid surface area determinations are desired.1.2 Because the single-point method uses an approximation of the BET equation, the multipoint BET method (Test Method D3663) is preferred to the single-point method.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 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 consult and 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.

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1.1 The purpose of this Guide is to provide methodologic information specific to highly graphitized, low surface area materials used in the nuclear industry. It applies to nitrogen adsorption measurements at 77 K for the characterization of graphite pore structure, such as: (1) specific surface area; (2) cumulative volume of open pores (for pore sizes less than about 300 nm); and (3) distribution of pore volumes as a function of pore sizes (for pore sizes less than about 30 nm). These properties are related to graphite’s reactivity in oxidative environments, graphite’s ability to retain fission products, and gas transport through graphite’s pore system.1.2 Characterization of surface area (also known as the Brunauer-Emmett-Teller “BET” method) and porosity in nuclear graphite by gas adsorption is challenged by nuclear graphite’s low specific surface area, weak adsorption interactions, and energetic and structural heterogeneity of surface sites in gas-accessible pores. This guide provides recommendations and practical information related to the nitrogen adsorption method, including guidance on specimen preparation, selection of experimental conditions, data processing, and interpretation of results.1.3 Other porosity characterization methods used for nuclear graphite, such as krypton adsorption at 77 K, argon adsorption at either 77 K or 87 K, helium pycnometry (Test Method B923), and mercury intrusion porosimetry, are not in the scope of this guide.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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.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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3.1 This test method is used to measure the surface area of precipitated, hydrated silicas that is available to the nitrogen molecule using the multipoint (B. E. T.) method. Single point nitrogen surface area is measured in accordance with the Test Methods D5604.3.2 Solids adsorb nitrogen, and under specific conditions, the adsorbed molecules approach a monomolecular layer. The quantity in this hypothetical monomolecular layer is calculated using the BET equation. Combining this with the area occupied by the nitrogen molecule yields the total surface area of the solid.3.3 This test method measures the estimated quantity of nitrogen in the monomolecular layer by adsorption at liquid nitrogen temperature and at several (at least five) partial pressures of nitrogen.3.4 Before a surface area determination can be made it is necessary that the silica be stripped of any material which may already be adsorbed on the surface. The stripping of adsorbed foreign material eliminates two potential errors. The first error is associated with the weight of the foreign material. The second error is associated with the surface area that the foreign material occupies.1.1 This test method covers a procedure which is used to measure the surface area of precipitated hydrated silicas by the conventional Brunauer, Emmett, and Teller (BET)2 theory of multilayer gas adsorption behavior using multipoint determinations, similar to that used for carbon black in Test Method D6556. This test method specifies the sample preparation and treatment, instrument calibrations, required accuracy and precision of experimental data, and calculations of the surface area results from the obtained data.1.2 This test method is used to determine the nitrogen surface area of precipitated silicas with specific surface areas in the range of 10 to 500 m2/g.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 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. The minimum safety equipment should include protective gloves, sturdy eye and face protection, and means to deal safely with accidental mercury spills.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.

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4.1 Both sellers and purchasers of alumina and quartz will find the test method useful to determine the specific surface area and indirectly as a measure of the particle size for material specifications, manufacturing control, and research and development.1.1 This test method covers the determination of the specific surface area of aluminas and silicas used in the manufacture of ceramics. The test method is a general one, permitting the use of any modern commercial nitrogen adsorption apparatus but strictly defining the outgassing procedure. Calculations are based on the Brunauer-Emmett-Teller (BET) equation.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.

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5.1 This guide is intended to determine meso- and macropore volume which affects heavy oil cracking performance of a catalyst. The information is useful for materials specification, manufacturing control, and research and development in the evaluation of catalytic materials.5.2 It has been reported in literature the existence of a correlation between the pore volume obtained from this guide and that from Test Method D4284.31.1 This guide measures pore volume of powdered catalysts and catalyst carriers by titration with water. The water does not react with material. The range of pore volume is 0.25 mL/g to 0.46 mL/g.1.2 This guide is suitable for fine catalysts such as fluid catalytic cracking (FCC) catalysts (fresh or equilibrium), catalyst additives and spray dried catalyst carriers or finished catalysts, or a combination thereof, and is typically applicable to powders with the majority of particles (above 90 %) in the distribution range between 20 and 150 µm equivalent spherical diameter (determined by Test Method D4464) and with an average particle size between 60 and 100 µm.NOTE 1: This technique is capable of measuring particles below and above this range (for example, from 1 to 300 µm) but no precision data is available.1.3 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.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.

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5.1 Activated carbon is used extensively for removing gases and vapors from air or other gas streams. The physical and chemical characteristics of an activated carbon can strongly influence its suitability for a given application. The procedure in this guide allows the evaluation of the dynamic adsorption characteristics of an activated carbon for a particular adsorbate under conditions chosen by the user. It is necessary that the user choose test conditions that are meaningful for the application (see Section 9).5.2 This guide can also be used to evaluate activated carbons that have been impregnated with materials to enhance their effectiveness at removing gases otherwise poorly adsorbed on activated carbon.5.3 The procedure given in this guide is not generally applicable for evaluation of carbons used as catalysts for such purposes as decomposition of low levels of ozone or oxidation of SO2 to SO3.5.4 The procedure given in this guide can be applied to reactivated or regenerated activated carbons.5.5 Fig. 1 shows the adsorbate concentration profile in an activated carbon bed at breakthrough. The bed has a zone at the inlet in which the adsorbate concentration is equal to the influent concentration. In this region the carbon is at equilibrium with adsorbate. The adsorbate concentration in the remainder of the bed drops until at the outlet it is equal to the breakthrough concentration. The shorter the length of this mass transfer zone (adsorption zone), the more effectively the carbon in the bed is utilized. A bed whose depth is less than the length of this zone will show immediate appearance of adsorbate in the effluent (breakpoint).FIG. 1 Concentration Profile of an Activated Carbon Bed at Breakthrough5.6 From the standpoint of best carbon utilization, it is desirable to choose a carbon which will give as short a mass transfer zone as possible under use conditions. However, in many applications, high adsorptive capacity is more important than a short mass transfer zone. In almost every application, bed pressure drop is also a primary consideration.5.7 In a few situations such as respiratory protection against low levels of extremely toxic gases such as radioactive methyl iodide, a short mass transfer zone (that is, high adsorption rate coefficient) is more important than ultimate capacity. In other cases such as solvent recovery, a high dynamic capacity is more important.5.8 Although the design of adsorber beds is beyond the scope of this guide, the following points should be considered. The bed diameter should be as large as possible in order to lower the pressure drop and to maximize the amount of carbon in the bed. Subject to pressure drop constraints, the deepest possible carbon bed should be used. All else being equal, the use of smaller particle size carbon will shorten the mass transfer zone and improve bed efficiency at the expense of higher pressure drop. If pressure drop considerations are critical, some particle morphologies offer less resistance to flow than others.5.9 The two parameters obtained by the procedure in this guide can be used as an aid in selecting an activated carbon and in sizing the adsorption bed in which this carbon will be used. The best carbon for most applications should have a high dynamic capacity for the adsorbate No coupled with a short mass transfer zone (small dc) when evaluated under the operating conditions anticipated for the adsorber.1.1 This guide covers the evaluation of activated carbons for gas-phase adsorption. It presents a procedure for determining the dynamic adsorption capacity, No, and critical bed depth, dc, for an activated carbon used to remove a specific adsorbate from a gas stream under conditions chosen by the user.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. Specific hazards statements are given in Section 7.1.4 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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