1、Designation: D7759 12aD7759/D7759M 14Standard Guide forNuclear Surface Moisture and Density Gauge Calibration1This standard is issued under the fixed designation D7759;D7759/D7759M; the number immediately following the designation indicatesthe year of original adoption or, in the case of revision, t
2、he year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This guide describes the process and objective of calibrating the density system of a nuclear surface mois
3、ture and densitygauge, or formulating the mathematical relationship between the density system response (the “density count”) of a nuclear surfacemoisture and density gauge and the corresponding density value of the density standard upon which the density system responsewas observed.1.2 This guide d
4、escribes the process and objective of calibrating the water content system of a nuclear surface moisture anddensity gauge, or formulating the mathematical relationship between the water content system response (the “water content count”)of a nuclear surface moisture and density gauge and the corresp
5、onding water mass per unit volume value of the water contentstandard upon which the water content system response was observed.1.3 This guide describes the process and objective of verifying the density system of a nuclear surface moisture and densitygauge.1.4 This guide describes the process and ob
6、jective of verifying the water content system of a nuclear surface moisture anddensity gauge.1.5 This guide describes two mathematical processes by which the gauge measurement precision may be computed ormeasured.1.6 This guide offers guidance for developing and reporting estimates of uncertainties
7、in measurements made with gauges thathave undergone calibration or verification.1.7 All observed and calculated values shall confirm to the guide for significant digits and rounding established in PracticeD6026.1.8 UnitsThe values stated in either SI units or inch pound units are to be regarded sepa
8、rately as standard. The values statedin each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining valuesfrom the two systems may result in non-conformance with the standard.1.9 This guide does not purport to address all of the safety concern
9、s, if any, associated with its use. It is the responsibility ofthe user of this guide to establish appropriate safety and health practices and determine the applicability of regulatory limitationsprior to use.1.10 This guide offers an organized collection of information or a series of options and do
10、es not recommend specific course ofaction. This document cannot replace education or experience and should be used in conjunction with professional judgment. Notall aspects of this guide may be applicable in all circumstances. This ASTM standard is not intended to represent or replace thestandard of
11、 care by which the adequacy of a given professional service must be judged, nor should this document be appliedwithout consideration of a projects many unique aspects. The word “Standard” in the title of this document means only that thedocument has been approved through the ASTM consensus process.2
12、. Referenced Documents2.1 ASTM Standards:2D653 Terminology Relating to Soil, Rock, and Contained FluidsD2216 Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass1 This practice is under the jurisdiction of ASTM Committee D18 on Soil and Rock and is the direc
13、t responsibility of Subcommittee D18.08 on Special and ConstructionControl Tests.Current edition approved Nov. 1, 2012June 1, 2014. Published December 2012July 2014. Originally approved in 2012. Last previous edition approved in 2012 asD775912.12a. DOI: 10.1520/D7759-12a.10.1520/D7759-14.2 For refer
14、encedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide th
15、e user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standa
16、rd as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1D3740 Practice for Minimum Requirements for Agencies En
17、gaged in Testing and/or Inspection of Soil and Rock as Used inEngineering Design and ConstructionD6026 Practice for Using Significant Digits in Geotechnical DataD6938 Test Method for In-Place Density and Water Content of Soil and Soil-Aggregate by Nuclear Methods (Shallow Depth)D7013 Guide for Nucle
18、ar Surface Moisture and Density Gauge Calibration Facility Setup3. Terminology3.1 DefinitionsSee Terminology D653 for general definitions.3.2 Definitions of Terms Specific to This Standard:3.2.1 coverage factor3, na number larger than one by which a combined standard measurement uncertainty is multi
19、plied toobtain an expanded measurement uncertainty.3.2.2 definitional uncertainty3, nthe component of measurement uncertainty resulting from the finite amount of detail in thedefinition of the measurand. The “measurand” in the case of a nuclear surface moisture density gauge, is typically either in-
20、placedensity or water mass per unit volume.3.2.3 density system calibration, nthe method by which the values of the fit parameters in the equation that relates the densitysystem response (the “density count”) of a nuclear gauge and the corresponding density value of the density standard upon whichth
21、at density system response was observed are computed. In addition, the uncertainty of measurements taken with gaugescalibrated by the specific method must be known at representative density values that span the range of densities for which thecalibration is valid.3.2.4 density system verification, n
22、a set of operations or processes, or both, by which, for each density standard used in theprocess, the in-place density value(s) measured by the nuclear gauge on the density standard is related to the corresponding value(s)of the standard or standards. In addition, the uncertainty of measurements ta
23、ken with gauges that meets the established verificationcriterion or criteria must be known at representative densities that span the range of densities for which the verification is valid.3.2.5 detector, na device to detect and measure radiation.3.2.6 expanded measurement uncertainty3, nproduct of a
24、 combined standard measurement uncertainty and a coverage factorlarger than one.3.2.7 gamma (radiation) source, na sealed source of radioactive material that emits gamma radiation as it decays.3.2.8 in-place density, nthe total mass (solids plus water) per total volume of soil or soil-aggregates mea
25、sured in place.3.2.9 measurement uncertainty3, nnon-negative parameter characterizing the dispersion of the quantity values being attributedto a measurand. The “measurand” in the case of a nuclear surface moisture density gauge, is typically either in-place density orwater mass per unit volume.3.2.1
26、0 neutron (radiation) source, na sealed source of radioactive material that emits neutron radiation as it decays.3.2.11 nuclear gauge, na device containing one or more radioactive sources used to measure certain properties of soil andsoil-aggregates.3.2.12 prepared standards, ndensity or water conte
27、nt measurement standards prepared of soil, solid rock, concrete, andengineered materials, that have density or water content values, or both, that are established and known to a specified uncertainty.3.2.13 source rod, na metal rod attached to a nuclear gauge in which a radioactive source or a detec
28、tor is housed. The rodcan be lowered to specified depths for testing.3.2.13 standard measurement uncertainty3, nmeasurement uncertainty expressed as a standard deviation.3.2.14 test count, N, nthe measured output of a detector for a specific type of radiation for a given test.3.2.15 Type A Uncertain
29、ty Evaluation3, nevaluation of a component of measurement uncertainty by a statistical analysis ofmeasured quantity values obtained under defined measurement conditions.3.2.16 Type B Uncertainty Evaluation3, nevaluation of a component of measurement uncertainty by means other than a TypeA Evaluation
30、.3.2.17 volumetric water content, nthe volume of water as a percent of the total volume of soil or rock material.3.2.18 water content, nthe ratio of the mass of water contained in the pore spaces of soil or soil-aggregate, to the solid massof particles in that material, expressed as a percentage (th
31、is is sometimes referred to in some scientific fields as gravimetric watercontent to differentiate it from volumetric water content).3.2.19 water content system calibration, nthe method by which the values of the fit parameters in the equation that relates thewater content system response (the “wate
32、r content count”) of a nuclear gauge and the corresponding water mass per unit volume3 JCGM 200:2008: International Vocabulary of MetrologyBasic and General Concepts and Associated Terms (VIM). 2008: Joint Document Committee for Guides inMetrology.D7759/D7759M 142value of the water content standard
33、upon which that water content system response was observed are computed. In addition, theuncertainty of measurements taken with the gauges calibrated by the specific method must be known at representative water massper unit volume values that span the range of water mass per unit volume values for w
34、hich the calibration is valid.3.2.20 water content system verification, na set of operations or processes, or both, by which, for each water content standardused in the process, the in-place water mass per unit volume value(s) measured by the nuclear gauge on water content standardis related to the
35、corresponding value(s) of these standards. In addition, the uncertainty of measurements taken with gauges thatmeets the established verification criterion or criteria must be known at representative water mass per unit volume values that spanthe range of water mass per unit volume values for which t
36、he verification is valid.3.2.21 water mass per unit volume, nthe ratio of the mass of water contained in the pore spaces of a soil or soil-aggregateto the total volume occupied by that soil or rock material.4. Summary of Practice4.1 The objectives of the practice are as follows:4.1.1 The objective o
37、f density system calibration is to formulate a mathematical equation, or density calibration equation, thatrelates the gauge density system response (the “density count”) to the soil-equivalent density of the standard on which this responseis elicited. The maximum uncertainties of subsequent gauge d
38、ensity readings shall be determined for the calibration process thatis used. The standards used for the determination of uncertainty shall be representative of the range of densities for which the gaugewill be used.4.1.2 The objective of density system verification is to evaluate the current density
39、 calibration equation for the gauge anddetermine if a new calibration is required. The verification method will be based upon relating, at the pertinent density or densitiesfor the specific method, the density value of a known density standard to the density measured by the gauge. The maximumuncerta
40、inties of subsequent gauge density readings shall be determined for the verification method used. The standards used forthe determination of uncertainty shall be representative of the range of densities for which the gauge will be used.4.1.3 The objective of water content system calibration is to fo
41、rmulate a mathematical equation, or water content calibrationequation, that relates the gauge water content system response (the “water content count”) to the water mass per unit volume valueof the standard on which this response is elicited. The uncertainties of subsequent gauge water mass per unit
42、 volume readings shallbe known for, at a minimum, a water mass per unit volume level within 32 kg/m3 (2.02.0 lbm/ft3) of the upper extreme of thewater mass per unit volume calibration range (typically 300 kg/m3 (18.718.7 lbm/ft3) or higher).4.1.4 The objective of water content system verification is
43、 to evaluate the current water content system calibration equation forthe gauge and determine if a new calibration is required. This evaluation will be based upon relating, at the pertinent water massper unit volume values for the specific method, the water mass per unit volume value of a known wate
44、r mass per unit volumestandard to the water mass per unit volume value measured by the gauge. The uncertainties of subsequent gauge water mass perunit volume readings shall be known for, at a minimum, a water mass per unit volume level within 32 kg/m3 (2.02.0 lbm/ft3)of the upper extreme of the wate
45、r mass per unit volume calibration range (typically 300 kg/m3 (18.718.7 lbm/ft3) or higher).4.1.5 The density calibration equation relates the in-place density value measured by the gauge on a test site (the “independentvariable”) with the density test count measured by the gauge on the test site (t
46、he “dependent variable”) is typically exponentialor polynomial in form, with three fit coefficients.4.2 Historically, the most successful methods for calibrating the density system of a gauge is done by taking gauge densityreadings on three or more density standards, combining the independent and de
47、pendent variables into data pairs, and using aleast-squares or Newton-Rafson fitting algorithm with these data pairs to compute the fit coefficients. These density standards haveunique density values that span the range of densities for which the gauge will be used.4.2.1 The density system calibrati
48、on of a gauge is not necessarily limited to the process described in 4.2. However, for anymethod that is used in the density system calibration process, one must know the uncertainties of the in-place density readingsmeasured by devices calibrated in this manner over the range of density values for
49、which the gauge will be used.4.2.2 For any method that is used in the density system verification process, one must know the uncertainties of the in-placedensity readings measured by devices calibrated in this manner over the range of density values for which the gauge will be used.4.2.3 The water content calibration equation that relates the in-place water mass per unit volume value measured by the gaugeon a test site (the “independent variable”) with the water content test count measured by the gauge on the test site (the “dependentvariable”) is
copyright@ 2008-2019 麦多课文库（www.mydoc123.com）网站版权所有
备案/许可证编号：苏ICP备17064731号-1