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定价： 927元 加购物车

5.1 This practice is consistent with a performance-based approach wherein the frequency of recalibration and instrument testing is linked to the results from continuing instrument quality control. Under the premise of this practice, a laboratory demonstrates that its instrument performance is acceptable for analyzing sample test sources.5.2 When a laboratory demonstrates acceptable performance based on continuing instrument quality control data (that is, control charts and tolerance charts), batch QC samples (that is, blanks, laboratory control samples, replicates, matrix spikes, and other batch QC samples as may be applicable) and independent reference materials, traditional schedule-driven instrument recalibration is permissible but unnecessary.5.3 When continuing instrument QC, batch QC, or independent reference material sample results indicate that instrument response has exceeded established control or tolerance limits, instrument calibration is required. Other actions related to sample analyses on the affected instruments may be required by the laboratory QM.5.4 The data obtained while following this practice will likely be stored electronically. The data remain in electronic storage, where they are readily available to produce plots, graphs, spreadsheets, and other types of displays and reports. The laboratory QM should specify the frequency and performance of data storage backup.1.1 This practice covers consensus criteria for the setup, calibration, and quality control of nuclear instruments. Setup establishes the operating parameters of the instrument—for example, voltage or discriminator settings. Calibrations determine the instrument’s response characteristics—for example, its counting efficiency or gain. Quality control ensures that the performance of the instrument remains acceptable for its intended use and consistent with the performance at the time of calibration.1.2 This practice addresses four of the most commonly used types of nuclear counting instruments: alpha-particle spectrometer, gamma-ray spectrometer, gas proportional counter, and liquid scintillation counter.1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions that are provided for information only and are not considered 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： 843元 加购物车

定价： 927元 加购物车

定价： 646元 加购物车

定价： 646元 加购物车

定价： 571元 加购物车

定价： 646元 加购物车

定价： 590元 加购物车

定价： 712元 加购物车

定价： 590元 加购物车

定价： 646元 加购物车

定价： 590元 加购物车

定价： 571元 加购物车

5.1 This Standard Test Method is intended for use in calibrating hand-held meters to accurately read from approximately 30 to 90 % ERH. Moisture content is related to the ERH or water activity of a material.5.2 Hand-held meters provide a rapid means of sampling the moisture content of gypsum boards and panels during manufacture and for field inspection during and after building construction. However, these measurements are inferential, that is, electrical parameters are measured and compared against a calibration curve to obtain an indirect measure of moisture content. The electrical measurements are influenced by the actual moisture content, a number of other gypsum board and panel variables, environmental conditions, the geometry of the measuring probe, and the design of the meter. The maximum accuracy can only be obtained by an awareness of the effect of each parameter on the meter output and correction of readings as specified by these test methods.5.3 Electrical conductance and dielectric meters are not necessarily equivalent in their readings under the same conditions. When this test method is referenced, the type of meter that is being used must be reported with the relevant ranges for precision and bias as specified in this standard.5.4 Both types of meters are to be calibrated with respect to ERH as described in this standard.1.1 This test method applies to the calibration of handheld moisture meters for gypsum board, glass faced gypsum panels and fiber-reinforced gypsum panels by means of electrical conductance and dielectric meters. The test uses wetted test specimens which are dried down in at least 5 steps to determine the moisture content based on the weight loss in comparison to the dry weight. The test also supplies the ERH values for each of the drying steps.1.2 This test method has not been evaluated for the influence of paint or wall covering materials on the indicated moisture content of a gypsum board or panel substrate.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