定价： 293元 / 折扣价： 250 元 加购物车

定价： 0元 / 折扣价： 0 元 加购物车

定价： 260元 / 折扣价： 221 元

定价： 260元 / 折扣价： 221 元

1.1 This test method covers the determination of the Vickers hardness of metallic materials, using applied forces of 1 kgf to 120 kgf, the verification of Vickers hardness testing machines (Part B), and the calibration of standardized hardness test blocks (Part C). Two general classes of standard tests are recognized:1.1.1 Verification, Laboratory, or Referee Tests, where a high degree of accuracy is required.1.1.2 Routine Tests, where a somewhat lower degree of accuracy is permissible.1.2 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 / 折扣价： 0 元

定价： 1976元 / 折扣价： 1680 元 加购物车

定价： 1333元 / 折扣价： 1134 元 加购物车

1.1 While there are a number of uses for interlaboratory tests, and variations in their design and implementation, it is still possible to specify the essential principles that need to be considered when organizing such tests. Part A of this guide defines those principles and describes the factors that should be taken into account in the organization and conduct of proficiency testing programs.1.2 This guide also covers how laboratory accrediting bodies, which assess technical competence of testing laboratories, should select and use proficiency testing programs (refer to Part B).1.3 Part A of the guide is intended for use by various parties, such as accrediting bodies, regulatory authorities and clients of laboratory services which have a need to assess the technical competence of laboratories. It is also useful for laboratories in self-evaluation, but recognizes that proficiency testing is only one mechanism that can contribute to establishing equivalent confidence among users of different testing laboratories.1.4 It is currently a condition of some accreditation bodies that laboratories participate regularly in "approved" proficiency testing programs. Therefore, it is essential that program operators comply with principles for conduct of professionally managed proficiency programs, both in terms of technical requirements and quality management (see Annex A1 and Annex A2).1.5 The methods of operation within different proficiency testing organizations are not expected to be identical and this guide does not give specific operational details for interlaboratory test comparisons. It does, however, cover both measurement comparison and testing programs in which large numbers of laboratories (over 20) or small groups of laboratories (1 to 20) are tested. Therefore, the contents of this guide are intended only as a framework to be modified appropriately for particular situations.1.6 A list of some relevant references is given in Appendix X1.

定价： 0元 / 折扣价： 0 元

Direct-reading polychromators are instruments commonly used for multi-element spectrochemical analysis. This guide seeks to describe those aspects of such instruments that are of significance in achieving useful spectrochemical performance. Awareness of parameters described in this practice will make manufacturers cognizant of factors they should consider in designing instruments, assist purchasers of instruments in making intelligent comparisons of competing designs, and make users aware of the compromises they must make in performing particular determinations.Adequate description of spectrometers permits forming qualified appraisals on three important performance characteristics: accuracy of analysis, detection limits, and freedom from line interferences.1.1 This guide covers features of a spectrometer or polychromator used for optical emission, direct-reading, spectrochemical analysis. A polychromator in this sense consists of a spectrometer with an extended and fixed wavelength range and an array of fixed exit slits to isolate the spectral lines of the elements to be measured.1.1.1 This guide does not apply to direct-reading systems that employ echelle spectrometers and vidicon or other detectors where the design parameters are quite different.1.2 This guide covers only the optical portion of the instrument, from excitation stand to photomultipliers.1.2.1 Only general statements are made about source units.1.2.2 Photomultipliers are included to the extent that they are mounted within the spectrometer to convert optical intensities to electrical signals, and establish the instrumental precision of each channel as a light measuring device. Readout systems are not included.1.3 It is not the purpose of this guide to establish binding specifications or tolerances, but rather, to call attention to important parameters that manufacturers should include in their literature, to provide methods for measuring those parameters, and to assign values that are indicative of acceptably good performance. Because of the great variety of demands imposed by spectrochemical techniques, rigid performance criteria are not feasible.1.4 The values stated in SI units are to be regarded as the standard.1.5 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 / 折扣价： 0 元

Isoaspartic acid residues are generated during incubation of proteins under a wide variety of conditions in aqueous solution. Such residues are generated most commonly through the deamidation of aspargine residues although some reports of isoaspartic acid formation through the rearrangement of aspartic acid residues have been published.The presence of such residues can indicate that the protein containing such residues has suffered damage that may affect the biological activity of the protein. The precise correlation between the level of isoaspartic acid content and the biological activity of the protein needs to be determined on a case by case basis.The test measures the level of isoaspartic acid content in a protein sample. This level will often be correlated with the degree to which the protein has suffered deamidation at asparagine residues. In addition, isoaspartic acid residues can arise on occasion through the rearrangement of aspartic acid residues. For these reasons, the level of isoaspartic acid residues in proteins can be used as a general indication that the protein sample has suffered some level of damage and should not be interpreted to indicate the precise level of damage to any one region within a protein without further testing.1.1 This test method covers the determination of isoaspartic acid residues in a protein or peptide sample. This test method is applicable for the determination of isoaspartic acid residues in a sample in the range of 2.5-50 μmol/L. Higher concentrations can be determined following dilution. The reported lower range is based on single-operator precision.1.2 The values stated in SI units are to be regarded as the 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 and health practices and determine the applicability of regulatory limitations prior to use.

定价： 0元 / 折扣价： 0 元

1.1 These test methods cover the testing of methylcellulose. 1.2 The test methods appear in the following order: Sections Moisture 4 and 5 Ash-as Sulfate 6 to 8 Chlorides-as Sodium Chloride 9 to 11 Alkalinity-as Na2CO3 12 to 14 Iron 15 to 19 Heavy Metals 20 to 22 Methoxyl Content 23 to 26 Viscosity: Water-Soluble Methylcellulose 27 to 29 Alkali-Soluble Methylcellulose 30 to 31 pH 32 Solids 33 to 34 Density 35 to 39 1.3 This standard does not purport to address 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.> For a specific hazard statement, see Note 1.

定价： 0元 / 折扣价： 0 元

1.1 This specification covers two types of diatomaceous silica pigments for use in paints: 1.1.1 Type A -Standard fineness for general paint use. 1.1.2 Type B -Extra fine, for special uses. Note 1-Silica pigments originating from crystalline rocks or sands are not covered by this specification. Note 2-For additional information, see Methods D719.

定价： 0元 / 折扣价： 0 元

1.1 This provisional standard is intended to provide performance requirements for pool alarms for residential swimming pools and spas.1.2 This provisional standard is intended to describe devices intended to improve personal safety and reduce injuries or deaths.1.3 This provisional standard covers devices that provide for rapid and automatic detection and alarm in cases of unintentional, unsupervised or accidental entry of a child one year of age or older into the water of swimming pools or spas.1.4 This provisional standard is not intended to replace other standard safety requirements that should be in place, that is, adult supervision, fences, gates, locks, etc.1.5 This standard covers four different types of alarms.1.6 The detection criteria for this standard is for a child one year of age and older.Note 1--Provisional standards require only subcommittee consensus and are published for a limited time of two years.

定价： 0元 / 折扣价： 0 元

1.1 This specification covers the red pigment commercially known as pure para red toner. It is available in two Types: Type I, light, and Type II, dark.

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1.1 This Guide covers the evaluation of gloss or flatted, unpigmented lacquers designed for use on wood substrates. This Guide is to be used in conjunction with Test Methods D333. Also included are several methods of special relevance to the application of lacquer on wood. The selection of the tests to be used for any given product or system must be governed by experience and by the requirements agreed upon by the producer and user. 1.2 The tests on films apply to those films applied in sufficient quantity to form a continuous film. It is recommended that reports include the thickness of the film under test. 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.

定价： 0元 / 折扣价： 0 元