定价： 646元 / 折扣价： 550 元 加购物车

定价： 646元 / 折扣价： 550 元 加购物车

This specification covers seamless and welded titanium and titanium alloy tubing on which the external or internal surface, or both, has been modified by a cold forming process to produce an integral enhanced surface for improved heat transfer. The tubes are used in surface condensers, evaporators, heat exchangers and similar heat transfer apparatus in unfinned end diameters of a specific size. Tubes shall be furnished with unenhanced ends in the annealed condition and shall be suitable for rolling-in operations. Each tube shall be subject to a nondestructive eddy current test, and either a pneumatic or hydrostatic test.1.1 This specification covers seamless and welded titanium and titanium alloy tubing on which at least part of the external or internal surface has been enhanced by cold forming for improved heat transfer. The tubes are used in surface condensers, evaporators, heat exchangers, coils, and similar heat transfer apparatus in diameters up to and including 1 in. [25.4 mm]. The base tube wall thickness is typically at least 0.049 in. [1.245 mm] average, but lighter gauge may be negotiated with the manufacturer.1.2 Tubing purchased to this specification will typically be inserted through close-fitting holes in tubesheets, baffles, or support plates spaced along the tube length such as defined in the Tubular Exchanger Manufacturer’s Association (TEMA) Standard.2 The tube ends will also be expanded, and may then be welded. Tube may also be bent to form U-tubes or be coiled or otherwise formed, although tight radii may require unenhanced length for the bends.1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the order. Combining values from the two systems may result in non-conformance. Within the text, the SI units are shown in brackets. The inch-pound units shall apply unless the “M” designation of this specification is specified in the order.1.4 The following precautionary statement pertains to the test method portion only: Section 8, 9, 10 and S1 of this specification: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 / 折扣价： 502 元 加购物车

5.1 This test method is applicable to the measurement of airborne asbestos in a wide range of ambient air situations and for detailed evaluation of any atmosphere for asbestos structures. Most fibers in ambient atmospheres are not asbestos, and therefore, there is a requirement for fibers to be identified. Most of the airborne asbestos fibers in ambient atmospheres have diameters below the resolution limit of the light microscope. This test method is based on transmission electron microscopy, which has adequate resolution to allow detection of small thin fibers and is currently the only technique capable of unequivocal identification of the majority of individual fibers of asbestos. Asbestos is often found, not as single fibers, but as very complex, aggregated structures, which may or may not also be aggregated with other particles. The fibers found suspended in an ambient atmosphere can often be identified unequivocally if sufficient measurement effort is expended. However, if each fiber were to be identified in this way, the analysis would become prohibitively expensive. Because of instrumental deficiencies or because of the nature of the particulate matter, some fibers cannot be positively identified as asbestos even though the measurements all indicate that they could be asbestos. Therefore, subjective factors contribute to this measurement, and consequently, a very precise definition of the procedure for identification and enumeration of asbestos fibers is required. The method defined in this test method is designed to provide a description of the nature, numerical concentration, and sizes of asbestos-containing particles found in an air sample. The test method is necessarily complex because the structures observed are frequently very complex. The method of data recording specified in the test method is designed to allow reevaluation of the structure-counting data as new applications for measurements are developed. All of the feasible specimen preparation techniques result in some modification of the airborne particulate matter. Even the collection of particles from a three-dimensional airborne dispersion on to a two-dimensional filter surface can be considered a modification of the particulate matter, and some of the particles, in most samples, are modified by the specimen preparation procedures. However, the procedures specified in this test method are designed to minimize the disturbance of the collected particulate material.5.2 This test method applies to analysis of a single filter and describes the precision attributable to measurements for a single filter (see 13.1). Multiple air samples are usually necessary to characterize airborne asbestos concentrations across time and space. The number of samples necessary for this purpose is proportional to the variation in measurement across samples, which may be greater than the variation in a measurement for a single sample.1.1 This test method2 is an analytical procedure using transmission electron microscopy (TEM) for the determination of the concentration of asbestos structures in ambient atmospheres and includes measurement of the dimension of structures and of the asbestos fibers found in the structures from which aspect ratios are calculated.1.1.1 This test method allows determination of the type(s) of asbestos fibers present.1.1.2 This test method cannot always discriminate between individual fibers of the asbestos and non-asbestos analogues of the same amphibole mineral.1.2 This test method is suitable for determination of asbestos in both ambient (outdoor) and building atmospheres.1.2.1 This test method is defined for polycarbonate capillary-pore filters or cellulose ester (either mixed esters of cellulose or cellulose nitrate) filters through which a known volume of air has been drawn and for blank filters.1.3 The upper range of concentrations that can be determined by this test method is 7000 s/mm2. The air concentration represented by this value is a function of the volume of air sampled.1.3.1 There is no lower limit to the dimensions of asbestos fibers that can be detected. In practice, microscopists vary in their ability to detect very small asbestos fibers. Therefore, a minimum length of 0.5 μm has been defined as the shortest fiber to be incorporated in the reported results.1.4 The direct analytical method cannot be used if the general particulate matter loading of the sample collection filter as analyzed exceeds approximately 10 % coverage of the collection filter by particulate matter.1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.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： 843元 / 折扣价： 717 元 加购物车

3.1 The primary use of this guide is to provide a standardized approach for the data file to be used for the transfer of digital radiological data from one user to another where the two users are working with dissimilar systems. This guide describes the contents, both required and optional for an intermediate data file that can be created from the native format of the radiological system on which the data was collected and that can be converted into the native format of the receiving radiological data analysis system. This guide will also be useful in the archival storage and retrieval of radiological data as either a data format specifier or as a guide to the data elements which should be included in the archival file.3.2 Although the recommended field listing includes more than 100 field numbers, only about half of those are regarded as essential and are marked Footnote C in Table 1. Fields so marked must be included in the data base. The other fields recommended provide additional information that a user will find helpful in understanding the radiological image and examination result. These header field items will, in most cases, make up only a very small part of a radiological examination file. The actual stream of radiological data that make up the image will take up the largest part of the data base. Since a radiological image file will normally be large, the concept of data compression will be considered in many cases. Compressed data should be noted, along with a description of the compression method, as indicated in Field No. 92 (see Table 1).(A) Field numbers are for reference only. They do not imply a necessity to include all these fields in any specific data base nor imply a requirement that fields used be in this particular order.(B) Units listed first are SI; those in parentheses are inch-pound (English).(C) Denotes essential field for computerization of examination results, regardless of examination method.(D) Denotes essential field for radiographic examination.(E) Denotes essential field for images with more than 8-bit gray scale.(F) Denotes essential field for radioscopic examination.3.3 This guide provides a data file for a single image. It is recognized that a complete examination record may contain several files for the same examination method in different areas, with or without image processing, for different examination methods, and for variations within a single method (for example, different X-ray energies). This file will permit the examination of a single image and will include information about the existence of other images and records for the examined object. This single image may be one created by overlaying or processing results from multiple examination approaches, for example, data fusion. For such images, the notes sections must clearly state how the image for this file was created.3.4 The Guide E1475 data fields are assigned at the TIFF group with Tag 50983, called Data fields of Guide E1475 using XML as format for the data fields. The tag may be used by any user without restrictions. The Extensible Markup Language (XML) is a simple, very flexible text format derived from SGML (ISO 8879). It is used to store all required information of Guide E1475 within one TIFF Tag. Annex A1 provides more information and an example.1.1 This guide provides a listing and description of the fields that are recommended for inclusion in a digital radiological examination data base to facilitate the transfer of such data. This guide sets guidelines for the format of data fields for computerized transfer of digital image files obtained from radiographic, radioscopic, computed radiographic, or other radiological examination systems. The field listing includes those fields regarded as necessary for inclusion in the data base: (1) regardless of the radiological examination method (as indicated by Footnote C in Table 1), (2) for radioscopic examination (as indicated by Footnote F in Table 1), and (3) for radiographic examination (as indicated by Footnote D in Table 1). In addition, other optional fields are listed as a reminder of the types of information that may be useful for additional understanding of the data or applicable to a limited number of applications.1.2 It is recognized that organizations may have in place an internal format for the storage and retrieval of radiological examination data. This guide should not impede the use of such formats since it is probable that the necessary fields are already included in such internal data bases, or that the few additions can easily be made. The numerical listing and its order indicated in this guide is only for convenience; the specific numbers and their order carry no inherent significance and are not part of the data file.1.3 Current users of Guide E1475 do not have to change their software. First time users should use the XML structure of Table A1.1 for their data.1.4 The types of radiological examination systems that appear useful in relation to this guide include radioscopic systems as described in Guide E1000, Practices E1255, E1411, E2597, E2698 and E2737, and radiographic systems as described in Guide E94 and Practices E748, E1742, E2033, E2445, and E2446. Many of the terms used are defined in Terminology E1316.1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.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 / 折扣价： 502 元 加购物车

5.1 Many materials that come into contact with drinking water have the potential of impacting the aesthetic quality of the water. Some of these diverse materials include: storage reservoirs, concrete or metal piping, or both, sealants, synthetic reservoir covers and liners, mending adhesives, gaskets, paints, and plastics. Though NSF Standard 61 provides testing for health effects, it does not address taste and odor implications. A Utility Quick Test (1),4 has been proposed, but has not been adopted as an official test standard. Taste and odor problems have been reported as a result of organic compounds leaching from approved materials into water. Materials only need to be tested if they come into direct contact with drinking water.1.1 This test method describes procedures for measuring odor and flavor properties of materials which may come into direct contact with municipal drinking water. For this method, “drinking water” will be considered water from the source (for example, river, lake, reservoir) through the municipal distribution system (that is, not including in-home or in-business taps). The focus of this test method is the evaluation of the materials in terms of their potential to transfer odors, flavors, or both to water.1.2 This test method provides sample preparation procedures, methods of sensory evaluation, and a process for interpretation of results.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. All materials that come into contact with drinking water are required to be approved through testing by accredited laboratories using NSF/ANSI Standard 61. 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： 590元 / 折扣价： 502 元 加购物车

定价： 590元 / 折扣价： 502 元 加购物车

5.1 This test method is designed for use by a trained sensory panel experienced in using an intensity scale or rank ordering and familiar with the descriptive terminology and references associated with the packaging materials. Data analysis and interpretation should be conducted by a trained and experienced sensory professional. See Refs (3, 4) for discussions on panelist screening and training.5.2 This test method should be considered as a screening technique for suppliers and end-users to use in assessing the odor or flavor impact or both of rigid packaging. The application of this test method will result in a PPS or rank data. The determination for suitability of a package for a particular end-use should be based on a set of predetermined criteria including the PPS or rank score. Information obtained from the transfer tests can also be used to evaluate the origin of any transferred tastes or odors.1.1 This test method covers a recommended procedure for examining odor or flavor properties or both of rigid polymeric packaging closures and fillable materials.1.2 This test method can be used for single materials or coextruded materials that are foam molded, injection molded, blow molded, compression molded, or thermoformed polymers.1.3 The focus of this test method is the evaluation of molded polymer in terms of the transfer of package-related odors, flavors, or both, to water and other model systems (bland food simulants). Rigid packaging forms vary considerably in type, size, and shape. Thus, customizing the exact procedure for dealing with the physical requirements for individual packages is the responsibility of the user.1.4 This test method assumes testing of the materials at a one-time point; shelf-life testing is not included.1.5 Refer to Test Method E1870 for the evaluation of inherent odor of packaging material by confinement tests.1.6 This test method provides sample preparation procedures and two methods of evaluation.1.6.1 The package performance score method allows for the comparison of any molded polymer sample to another.1.6.2 The ranking method allows for comparison of samples within the currently tested set only.1.6.3 The preparation of samples is consistent regardless of the method of evaluation used.1.7 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.8 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.1.9 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 / 折扣价： 502 元 加购物车

5.1 There are several purposes of this test:5.1.1 For transmission loss: (a) to characterize the sound insulation characteristics of materials in a less expensive and less time consuming approach than Test Method E90 and ISO 140-3 (“reverberant room methods”), (b) to allow small samples tested when larger samples are impossible to construct or to transport, (c) to allow a rapid technique that does not require an experienced professional to run.5.1.2 For transfer matrix: (a) to determine additional acoustic properties of the material; (b) to allow calculation of acoustic properties of built-up or composite materials by the combination of their individual transfer matrices.5.2 There are significant differences between this method and that of the more traditional reverberant room method. Specifically, in this approach the sound impinges on the specimen in a perpendicular direction (“normal incidence”) only, compared to the random incidence of traditional methods. Additionally, revereration room methods specify certain minimum sizes for test specimens which may not be practical for all materials. At present the correlation, if any, between the two methods is not known. Even though this method may not replicate the reverberant room methods for measuring the transmission loss of materials, it can provide comparison data for small specimens, something that cannot be done in the reverberant room method. Normal incidence transmission loss may also be useful in certain situations where the material is placed within a small acoustical cavity close to a sound source, for example, a closely-fitted machine enclosure or portable electronic device.5.3 Transmission loss is not only a property of a material, but is also strongly dependent on boundary conditions inherent in the method and details of the way the material is mounted. This must be considered in the interpretation of the results obtained by this test method.5.4 The quantities are measured as a function of frequency with a resolution determined by the sampling rate, transform size, and other parameters of a digital frequency analysis system. The usable frequency range depends on the diameter of the tube and the spacing between the microphone positions. An extended frequency range may be obtained by using tubes with various diameters and microphone spacings.5.5 The application of materials into acoustical system elements will probably not be similar to this test method and therefore results obtained by this method may not correlate with performance in-situ.1.1 This test method covers the use of a tube, four microphones, and a digital frequency analysis system for the measurement of normal incident transmission loss and other important acoustic properties of materials by determination of the acoustic transfer matrix.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： 646元 / 折扣价： 550 元 加购物车

4.1 The purpose of this test method is to measure the rate of thermal energy per unit area transferred into a known piece of material (slug) for purposes of calibrating the thermal environment into which test specimens are placed for evaluation. The calorimeter and holder size and shape should be identical to that of the test specimen. In this manner, the measured heat transfer rate to the calorimeter can be related to that experienced by the test specimen.4.2 The slug calorimeter is one of many calorimeter concepts used to measure heat transfer rate. This type of calorimeter is simple to fabricate, inexpensive, and readily installed since it is not water-cooled. The primary disadvantages are its short lifetime and relatively long cool-down time after exposure to the thermal environment. In measuring the heat transfer rate to the calorimeter, accurate measurement of the rate of rise in back-face temperature is imperative.4.3 In the evaluation of high-temperature materials, slug calorimeters are used to measure the heat transfer rate on various parts of the instrumented models, since heat transfer rate is one of the important parameters in evaluating the performance of ablative materials.4.4 Regardless of the source of thermal energy to the calorimeter (radiative, convective, or a combination thereof) the measurement is averaged over the calorimeter surface. If a significant percentage of the total thermal energy is radiative, consideration should be given to the emissivity of the slug surface. If non-uniformities exist in the input energy, the heat transfer rate calorimeter would tend to average these variations; therefore, the size of the sensing element (that is, the slug) should be limited to small diameters in order to measure local heat transfer rate values. Where large ablative samples are to be tested, it is recommended that a number of calorimeters be incorporated in the body of the test specimen such that a heat transfer rate distribution across the heated surface can be determined. In this manner, more representative heat transfer rate values can be defined for the test specimen and thus enable more meaningful interpretation of the test. The slug selection may be determined using the nomogram as a guide (see Appendix X1).1.1 This test method describes the measurement of heat transfer rate using a thermal capacitance-type calorimeter which assumes one-dimensional heat conduction into a cylindrical piece of material (slug) with known physical properties.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.NOTE 1: For information see Test Methods E285, E422, E458, E459, and E511.1.3 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： 590元 / 折扣价： 502 元 加购物车

5.1 This test method may be used to measure the net heat transfer rate to a metallic or coated metallic surface for a variety of applications, including:5.1.1 Measurements of aerodynamic heating when the calorimeter is placed into a flow environment, such as a wind tunnel or an arc jet; the calorimeters can be designed to have the same size and shape as the actual test specimens to minimize heat transfer corrections;5.1.2 Heat transfer measurements in fires and fire safety testing;5.1.3 Laser power and laser absorption measurements; as well as,5.1.4 X-ray and particle beam (electrons or ions) dosimetry measurements.5.2 The thin-skin calorimeter is one of many concepts used to measure heat transfer rates. It may be used to measure convective, radiative, or combinations of convective and radiative (usually called mixed or total) heat transfer rates. However, when the calorimeter is used to measure radiative or mixed heat transfer rates, the absorptivity and reflectivity of the surface should be measured over the expected radiation wavelength region of the source, and as functions of temperature if possible.5.3 In 6.6 and 6.7, it is demonstrated that lateral heat conduction effects on a local measurement can be minimized by using a calorimeter material with a low thermal conductivity. Alternatively, a distribution of the heat transfer rate may be obtained by placing a number of thermocouples along the back surface of the calorimeter.5.4 In high temperature or high heat transfer rate applications, the principal drawback to the use of thin-skin calorimeters is the short exposure time necessary to ensure survival of the calorimeter such that repeat measurements can be made with the same sensor. When operation to burnout is necessary to obtain the desired heat flux measurements, thin-skin calorimeters are often a good choice because they are relatively inexpensive to fabricate.5.5 It is important to understand that the calorimeter design (that is, that shown in Fig. 1) will measure the “net” heat flux into the thin-skin calorimeter. This configuration may or may not be the same as the test specimen of interest. If it is the same configuration, then the results from use of Eq 1 can be used directly. But if the configuration is different, then some additional analysis should be performed. For example, if the actual test specimen has an insulated layer on the inside surface of the thin-skin, but the thin-skin calorimeter does not, then the net heat flux from Eq 1 will not be the same as the response of the test specimen. Refer to Appendix X1 for further discussion of this topic.1.1 This test method covers the design and use of a thin metallic calorimeter for measuring heat transfer rate (also called heat flux). Thermocouples are attached to the unexposed surface of the calorimeter. A one-dimensional heat flow analysis is used for calculating the heat transfer rate from the temperature measurements. Applications include aerodynamic heating, laser and radiation power measurements, and fire safety testing.1.2 Advantages: 1.2.1 Simplicity of Construction—The calorimeter may be constructed from a number of materials. The size and shape can often be made to match the actual application. Thermocouples may be attached to the metal by spot, electron beam, or laser welding.1.2.2 Heat transfer rate distributions may be obtained if metals with low thermal conductivity, such as some stainless steels or Inconel 600, are used.1.2.3 The calorimeters can be fabricated with smooth surfaces, without insulators or plugs and the attendant temperature discontinuities, to provide more realistic flow conditions for aerodynamic heating measurements.1.2.4 The calorimeters described in this test method are relatively inexpensive. If necessary, they may be operated to burn-out to obtain heat transfer information.1.3 Limitations: 1.3.1 At higher heat flux levels, short test times are necessary to ensure calorimeter survival.1.3.2 For applications in wind tunnels or arc-jet facilities, the calorimeter must be operated at pressures and temperatures such that the thin-skin does not distort under pressure loads. Distortion of the surface will introduce measurement errors.1.3.3 Interpretation of the heat flux estimated may require additional analysis if the thin-skin calorimeter configuration is different from the test specimen.1.4 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4.1 Exception—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.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： 646元 / 折扣价： 550 元 加购物车

定价： 590元 / 折扣价： 502 元 加购物车

定价： 646元 / 折扣价： 550 元 加购物车

定价： 515元 / 折扣价： 438 元 加购物车

5.1 Most commercial reflectometers and spectrophotometers with reflectance capability measure relative reflectance. The instrument reading is the ratio of the measured radiation reflected from the reference specimen to the measured radiation reflected by the test specimen. That ratio is dependent on specific instrument parameters.5.2 National standardizing laboratories and some research laboratories measure reflectance on instruments calibrated from basic principles, thereby establishing a scale of absolute reflectance as described in CIE Publication No. 44 (5). These measurements are sufficiently difficult and of prohibitive cost that they are usually left to laboratories that specialize in them.5.3 A standard that has been measured on an absolute scale could be used to transfer that scale to a reflectometer. While such procedures exist, the constraints placed on the mechanical properties restrict the suitability of some of the optical properties, especially those properties related to the geometric distribution of reflected radiation. Thus, reflectance factor standards that are sufficiently rugged or cleanable to use as permanent transfer standards, with the exception of the sintered PTFE standards, depart considerably from the perfect diffuser in the geometric distribution of reflected radiation.5.4 The geometric distribution of reflected radiance from such standards is sufficiently diffuse that such a standard can provide a dependable calibration of a directional-hemispherical or certain directional-directional reflectometers. Although pressed powder standards are subject to contamination and breakage, the reflectance factor of pressed powder can be sufficiently reproducible from specimen to specimen from a given lot of powder to allow the assignment of absolute reflectance factor values to all of the powder in a lot.5.5 Sintered PTFE materials exhibit sufficient reproducibility from within the same specimen after resurfacing or cleaning the specimen to allow the assignment of absolute reflectance factor values.5.6 Preparation of packed powder reflectance standards is covered in Practice E259. This practice describes the spectral and physical properties of these materials and of the sintered PTFE materials.1.1 This practice covers procedures for the preparation and use of acceptable transfer standards for NIR spectrophotometers. Procedures for calibrating the reflectance factor of materials on an absolute basis are contained in CIE Publication No. 44 (9). Both the pressed powder samples and the sintered PTFE materials are used as transfer standards for such calibrations because they have very stable reflectance factors that are nearly constant with wavelength and because the distribution of flux resembles closely that from the perfect reflecting diffuser.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 / 折扣价： 438 元 加购物车