5.1 This test method is intended for use in the laboratory or in the field for evaluating the cleanliness of distillate fuels, and liquid bio fuels. It is not applicable to on or in-line applications.5.2 This test method offers advantage over traditional filtration methods in that it is a precise rapid test, and advantage over visual methods as it is not subjective.5.3 An increase in particle counts can indicate a change in the fuel condition caused by storage or transfer for example.5.4 High levels of particles can cause filter blockages and have a serious impact on the life of pumps, injectors, pistons and other moving parts. Knowledge of particle size in relation to the metallurgy can provide vital information especially if the hardness of particles is also known from other sources.5.5 This test method specifies a minimum requirement for reporting measurements in particle size bands (see A1.1.2). Some specific applications may require measurements in other particle size bands.5.6 Obtaining a representative sample and following the recommended sample and test specimen preparation procedures and timescales is particularly important with particle counting methods. (See Sections 8, 10, 14.1.4 and Note 8.)5.7 This test method can also be used to estimate the total particulate counts excluding free water droplets in aviation turbine fuels by a chemical pretreatment of the fuel. See Appendix X2.1.1 This test method uses a specific automatic particle counter2 (APC) to count and measure the size of dispersed dirt particles, water droplets and other particles, in light and middle distillate fuel, and bio fuels such as biodiesel and biodiesel blends, in the overall range from 4 µm(c) to 100 µm(c) and in the size bands ≥4 µm(c), ≥6 µm(c), and ≥14 µm(c).NOTE 1: ASTM and military specification fuels falling within the scope of this test method include Specifications: D975 grades 1D and 2D, D1655, D3699, D4814 (see 14.1.1.1), D6751, D7467, distillate grades of D396 and D2880, MIL-DTL-83133, and MIL-DTL-16884.NOTE 2: For the purposes of this test method, water droplets are counted as particles, and agglomerated particles are detected and counted as a single larger particle. Dirt includes biological particles. Although the projected area of a particle is measured, this is expressed as the diameter of a sphere for the purposes of this test method.NOTE 3: The notation (c), used with particle sizes, is used to denote that the apparatus has been calibrated in accordance with ISO 11171. Strictly this only applies to particles up to 50 µm.NOTE 4: This test method may be used for particle sizes bands up to 100 µm(c), however the precision has only been determined for the size bands ≥4 µm(c), ≥6 µm(c), and ≥14 µm(c). All measurements are per millilitre.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 加购物车

定价： 646元 加购物车

4.1 This test method permits a user to compare the performance of an instrument to the tolerance limit specifications stated by a manufacturer and to verify that an instrument is suitable for continued routine use. It also provides for generation of calibration data on a periodic basis, forming a database from which any changes in the performance of the instrument will be evident.4.2 This test method for the calibration verification of laser diffraction particle sizing instruments is suitable for acceptance testing of laser diffraction instruments so long as current estimates of the bias (see Section 11) and the between-laboratory precision of the test method (see Section 10) are acceptably small relative to typical laser diffraction instrument accuracy specifications; see Practice D3244.1.1 This test method describes a procedure necessary to permit a user to easily verify that a laser diffraction particle sizing instrument is operating within tolerance limit specifications, for example, such that the instrument accuracy is as stated by the manufacturer. The recommended calibration verification method provides a decisive indication of the overall performance of the instrument at the calibration point or points, but it is specifically not to be inferred that all factors in instrument performance are verified. In effect, use of this test method will verify the instrument performance for applications involving spherical particles of known refractive index where the near-forward light scattering properties are accurately modeled by the instrument data processing and data reduction software. The precision and bias limits presented herein are, therefore, estimates of the instrument performance under ideal conditions. Nonideal factors that could be present in actual applications and that could significantly increase the bias errors of laser diffraction instruments include vignetting4 (that is, where light scattered at large angles by particles far away from the receiving lens does not pass through the receiving lens and therefore does not reach the detector plane), the presence of nonspherical particles, the presence of particles of unknown refractive index, and multiple scattering.1.2 This test method shall be used as a significant test of the instrument performance. While the procedure is not designed for extensive calibration adjustment of an instrument, it shall be used to verify quantitative performance on an ongoing basis, to compare one instrument performance with that of another, and to provide error limits for instruments tested.1.3 This test method provides an indirect measurement of some of the important parameters controlling the results in particle sizing by laser diffraction. A determination of all parameters affecting instrument performance would come under a calibration adjustment procedure.1.4 This test method shall be performed on a periodic and regular basis, the frequency of which depends on the physical environment in which the instrumentation is used. Thus, units handled roughly or used under adverse conditions (for example, exposed to dust, chemical vapors, vibration, or combinations thereof) shall undergo a calibration verification more frequently than those not exposed to such conditions. This procedure shall be performed after any significant repairs are made on an instrument, such as those involving the optics, detector, or electronics.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 problems, 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： 646元 加购物车

定价： 646元 加购物车

This test method covers the apparatuses required, sampling methods, standard procedures and calculations, and test reports for counting and sizing airborne microparticulate matter, the sampling areas for which are specifically those with contamination levels typical of cleanrooms and dust-controlled areas. The test method is based on the microscopical examination of particles impinged upon a membrane filter with the aid of a vacuum. Sampling may be done in a cleanroom, clean zone, or other controlle areas, or in a duct or pipe, wherein the number of sampling points is proportional to the floor area of the enclosure to be checked. The apparatus and facilities required are typical of a laboratory for the study of macroparticle contamination. The operator must have adequate basic training in microscopy and the techniques of particle sizing and counting.1.1 This test method covers counting and sizing airborne particulate matter 5 µm and larger (macroparticles). The sampling areas are specifically those with contamination levels typical of cleanrooms and dust-controlled areas.1.2 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.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 加购物车

定价： 646元 加购物车

3.1 The electrical sensing zone method for cell counting is used in tissue culture, government research, and hospital, biomedical, and pharmaceutical laboratories for counting and sizing cells. The method may be applicable to a wide range of cells sizes and cell types, with appropriate validation (10).3.2 The electrical sensing zone methodology was introduced in the mid-1950s (9). Since this time, there have been substantial improvements which have enhanced the operator's ease of use. Among these are the elimination of the mercury manometer, reduced size, greater automation, and availability of comprehensive statistical computer programs.3.3 This instrumentation offers a rapid result as contrasted to the manual counting of cells using the hemocytometer standard counting chamber. The counting chamber is known to have an error of 10 to 30 %, as well as being time-consuming (11). In addition, when counting and sizing porcine hepatocytes, Stegemann et al concluded that the automated, electrical sensing zone method provided greater accuracy, precision, and speed, for both counts and size, compared to the conventional microscopic or the cell mass-based method (7).1.1 This test method, provided the limitations are understood, covers a procedure for both the enumeration and measurement of size distribution of most all cell types. The instrumentation allows for user-selectable cell size settings and is applicable to a wide range of cell types. The method works best for spherical cells, and may be less accurate if cells are not spherical, such as for discoid cells or budding yeast. The method is appropriate for suspension as well as adherent cell cultures (1).2 Results may be reported as number of cells per milliliter or total number of cells per volume of cell suspension analyzed. Size distribution may be expressed in cell diameter or volume.1.2 Cells commonly used in tissue-engineered medical products (2) are analyzed routinely. Examples are chondrocytes (3), fibroblasts (4), and keratinocytes (5). Szabo et al. used the method for both pancreatic islet number and volume measurements (6). In addition, instrumentation using the electrical sensing zone technology was used for both count and size distribution analyses of porcine hepatocytes placed into hollow fiber cartridge extracorporeal liver assist systems. In this study (7), and others (6, 8), the automated electrical sensing zone method was validated for precision when compared to the conventional visual cell counting under a microscope using a hemocytometer. Currently, it is not possible to validate cell counting devices for accuracy, since there not a way to produce a reference sample that has a known number of cells. The electrical sensing zone method shall be validated each time it is implemented in a new laboratory, it is used on a new cell type, or the cell counting procedure is modified.1.3 Electrical sensing zone instrumentation (commonly referred to as a Coulter counter) is manufactured by a variety of companies and is based upon electrical impedance. This test method, for cell counting and sizing, is based on the detection and measurement of changes in electrical resistance produced by a cell, suspended in a conductive liquid, traversing through a small aperture (see Fig. 1(9)). When cells are suspended in a conductive liquid, phosphate-buffered saline for instance, they function as discrete insulators. When the cell suspension is drawn through a small cylindrical aperture, the passage of each cell changes the impedance of the electrical path between two submerged electrodes located on each side of the aperture. An electrical pulse, suitable for both counting and sizing, results from the passage of each cell through the aperture. The path through the aperture, in which the cell is detected, is known as the “electronic sensing zone.” This test method permits the selective counting of cells within narrow size distribution ranges by electronic selection of the generated pulses. While the number of pulses indicates cell count, the amplitude of the electrical pulse produced depends on the cell's volume. The baseline resistance between the electrodes is due to the resistance of the conductive liquid within the boundaries of the aperture. The presence of cells within the “electronic sensing zone” raises the resistance of the conductive pathway that depends on the volume of the cell. Analyses of the behavior of cells within the aperture demonstrates that the height of the pulse produced by the cell is the parameter that most nearly shows proportionality to the cell volume.1.4 Limitations are discussed as follows:1.4.1 Coincidence—Occasionally, more than a single cell transverses the aperture simultaneously. Only a single larger pulse, as opposed to two individual pulses, is generated. The result is a lower cell count and higher cell volume measurement. The frequency of coincidence is a statistically predictable function of cell concentration that is corrected by the instrument. This is called coincidence correction (8). This phenomenon may be reduced by using lower cell concentrations.1.4.2 Viability—Electrical sensing zone cell counting enumerates both viable and nonviable cells and cannot determine percent viable cells. A separate test, such as Trypan blue, is required to determine percent viable cells.1.4.3 Cell Diameter—This is a function of the size range capability of the aperture size selected. Measurements may be made in the cell diameter range of 0.6 μm to 1200 μm. Setting the counting size range on the instrument can affect the test results, especially if the cell size has a large distribution, and should be carefully controlled to help achieve repeatability.1.4.4 Size Range of the Aperture—The size range for a single aperture is proportional to its diameter. The response has been found to depend linearly on diameter over a range from 2 % to 80 % of the diameter. However, the aperture tube may become prone to blockage at levels greater than 60 % of diameter. Therefore, the practical operating range of the aperture is considered to be 2 % to 60 % of the diameter.1.4.5 Humidity—10 % to 85 %.1.4.6 Temperature—10 °C to 35 °C.1.4.7 Electrolyte Solution—The diluent for cell suspension shall provide conductivity and have minimal effect on cell size. The electrolyte of choice is commonly phosphate-buffered saline.

定价： 515元 加购物车

定价： 515元 加购物车

5.1 The primary purpose of this practice is to describe a procedure for collecting near real-time data on airborne particle concentration and size distribution in clean areas as indicated by single particle counting techniques. Implementation of some government and industry specifications requires acquisition of particle size and concentration data using an SPC.5.2 The processing requirements of many products manufactured in a clean room involves environmental cleanliness levels so low that a single particle counter with capability for detecting very small particles is required to characterize clean room air. Real-time information on concentration of airborne particles in size ranges from less than 0.1 μm to 5 μm and greater can be obtained only with an SPC. Definition of particles larger than approximately 0.05 μm may be carried out with direct measurement of light scattering from individual particles; other techniques may be required for smaller particles, such as preliminary growth by condensation before particle measurement.5.3 Particle size data are referenced to the particle system used to calibrate the SPC. Differences in detection, electronic and sample handling systems among the various SPCs may contribute to differences in particle characterization. Care must be exercised in attempting to compare data from particles that vary significantly in composition or shape from the calibration base material. Variations may also occur between instruments using similar particle sensing systems with different operating parameters. These effects should be recognized and minimized by using standard methods for SPC calibration and operation.5.4 In applying this practice, the fundamental assumption is made that the particles in the sample passing through the SPC are representative of the particles in the entire dust-controlled area being analyzed. Care is required that good sampling procedures are used and that no artifacts are produced at any point in the sample handling and analysis process; these precautions are necessary both in verification and in operation of the SPC.1.1 This practice covers the determination of the particle concentration, by number, and the size distribution of airborne particles in dust-controlled areas and clean rooms, for particles in the size range of approximately 0.01 to 5.0 μm. Particle concentrations not exceeding 3.5 × 106 particles/m 3 (100 000/ft3) are covered for all particles equal to and larger than the minimum size measured.1.2 This practice uses an airborne single particle counting device (SPC) whose operation is based on measuring the signal produced by an individual particle passing through the sensing zone. The signal must be directly or indirectly related to particle size.NOTE 1: The SPC type is not specified here. The SPC can be a conventional optical particle counter (OPC), an aerodynamic particle sizer, a condensation nucleus counter (CNC) operating in conjunction with a diffusion battery or differential mobility analyzer, or any other device capable of counting and sizing single particles in the size range of concern and of sampling in a cleanroom environment.1.3 Individuals performing tests in accordance with this practice shall be trained in use of the SPC and shall understand its operation.1.4 Since the concentration and the particle size distribution of airborne particles are subject to continuous variations, the choice of sampling probe configuration, locations, and sampling times will affect sampling results. Further, the differences in the physical measurement, electronic, and sample handling systems between the various SPCs and the differences in physical properties of the various particles being measured can contribute to variations in the test results. These differences should be recognized and minimized by using a standard method of primary calibration and by minimizing variability of sample acquisition procedures.1.5 Sample acquisition procedures and equipment may be selected for specific applications based on varying cleanroom class levels. Firm requirements for these selections are beyond the scope of this practice; however, sampling practices shall be stated that take into account potential spatial and statistical variations of suspended particles in clean rooms.NOTE 2: General references to cleanroom classifications follow Federal Standard 209E, latest revision. Where airborne particles are to be characterized in dust-controlled areas that do not meet these classifications, the latest revision of the pertinent specification for these areas shall be used.1.6 Units—The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific hazards statements, see Section 8.1.8 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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定价： 646元 加购物车

定价： 590元 加购物车

5.1 This test method is intended for use in the laboratory or in the field to evaluate the cleanliness of distillate fuels, and liquid biofuels, such as biodiesel and diesel blends. This specific test method and the precision statement applies to off-line analysis.NOTE 5: These PCMs can be used for high pressure on-line applications as well, however the repeatability (r) and reproducibility (R) for on-line application were not established.5.2 An increase in particulate counts can indicate a change in the fuel condition caused for example by contamination during storage or transfer. Potential causes of particulates formation during storage could be “fuel-degradation products,” as described in Specification D975, Appendix X3.5.3 High levels of particles can cause filter blockages (especially when the particles are close in size to the filter porosity rating) and have a serious impact on the life of pumps, injectors, pistons, and other moving parts. Knowledge of particle size in relation to the metallurgy can provide vital information, especially if the hardness of particles is also known from other sources.5.4 This test method specifies a minimum requirement for reporting measurements in particle size bands (A1.2.1). Some specific applications may require measurements in other particle size bands. The particle count from the test should be carefully interpreted by the user as it can potentially over-state risk of abrasive damage or filter blocking due to counting water droplets as well as hard dirt particles.5.5 In situations where there is a requirement for the calibration of the apparatus to be solely in accordance with ISO 11171, Test Methods D7619, IP 565, or IP 577 may be used.1.1 This test method uses specific particle contamination monitors (PCMs) to count and measure the size of dispersed dirt particles, water droplets and other particulates, in middle distillate fuel, in the overall range from 4 µm to 70 µm and in the size bands ≥4 µm, ≥6 µm, ≥14 µm, and ≥30 µm.NOTE 1: The term particle contamination monitor, as used in this test method, is the same as that defined in ISO 21018-4; an instrument that automatically measures the concentrations of particles suspended in a fluid at certain sizes and cannot be calibrated in accordance with ISO 11171 whose output may be as a particle size distribution at limited sizes or as a contamination code.1.2 This test method has interim repeatability precision only, see Section 14 for more information.NOTE 2: ASTM specification fuels falling within the scope of this test method include Specifications: D975, D1655, D3699, D7467, MIL-DTL-83133, MIL-DTL-5624, and distillate grades of D396 and D2880.NOTE 3: For the purposes of this test method, water droplets are counted as particles, and agglomerated particles are detected and counted as a single larger particle. Dirt includes microbial particulates. Although the projected area of a particle is measured, this is expressed as the diameter of a circle for the purposes of this test method. The detector is unable to distinguish between dirt and water particles.NOTE 4: This test method may be used for particle sizes bands up to 70 µm, however the interim repeatability has only been determined for the size bands ≥4 µm, ≥6 µm, and ≥14 µm. All measurements are counts per millilitre.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.

定价： 590元 加购物车

定价： 260元 / 折扣价： 221 元 加购物车

定价： 260元 / 折扣价： 221 元 加购物车

定价： 260元 / 折扣价： 221 元 加购物车