5.1 Gauge calibration is performed for the following purposes:

5.1.1 When necessary, to compute the calibration constants of a density calibration equation that relates the gauge density system response (the “density count”) to the soil-equivalent density of the standard on which this response is elicited.

5.1.2 When necessary, to compute the calibration constants of a water content calibration equation that relates the gauge water content system response (the “water content count”) to the water mass per unit volume value of the standard on which this response is elicited.

5.1.3 To establish the relationship between the density measured by the gauge to the soil-equivalent density of the standard on which this response is elicited.

5.1.4 To establish the relationship between the water mass per unit volume measured by the gauge to the water mass per unit volume of the standard on which this response is elicited.

5.1.5 To ensure that the gauge has an in-place density gauge precision level that is consistent with typical gauge response.

5.1.6 To ensure that the gauge has an in-place water mass per unit volume gauge precision level that is consistent with typical gauge response.

5.2 Gauge verification is performed for the following purposes:

5.2.1 To indicate to the party or agency performing the verification when the mathematical relationship between the in-place density reading indicated by the gauge and the corresponding gauge density test count needs to be adjusted so that the gauge measurement errors do not exceed the specified absolute maximum measurement error for the calibration method used.

5.2.2 To indicate to the party or agency performing the verification when the mathematical relationship between the water mass per unit volume indicated by the gauge and the corresponding gauge water content test count needs to be adjusted so that the gauge measurement errors do not exceed the specified absolute maximum measurement error for the calibration method used.

5.2.3 Gauge verification and calibration require specialized training and equipment. Gauge calibration and verification are best conducted by those trained in the proper operation of the gauge, the calibration standards, and any tables, charts, graphs, or computer programs required for the proper execution of these operations.

Note 1: The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.

1.1 Procedure A—This guide describes the process and objective of formulating the mathematical relationship between the density system count of a nuclear surface moisture and density gauge and the corresponding wet density value of the density standard upon which the density system response was observed.

1.2 Procedure B—This guide describes the process and objective of comparing the wet density measured by a nuclear surface moisture and density gauge and the corresponding density value of the density standard upon which the density system response was observed.

1.3 This guide describes the process and objective of the verification of the measurements of a nuclear surface moisture and density gauge.

1.4 Procedure A—This guide describes the process and objective of formulating the mathematical relationship between the water content system count of a nuclear surface moisture and density gauge and the corresponding water mass per unit volume value of the water content standard upon which the water content system response was observed.

1.5 Procedure B—This guide describes the process and objective of comparing the water mass per unit volume measured by a nuclear surface moisture and density gauge and the corresponding water mass per unit volume of the corresponding water content standard upon which the water content system response was observed.

1.6 This guide describes the process and objective of the verification of the measurements of a nuclear surface moisture and density gauge.

1.7 This guide describes two mathematical processes by which the gauge measurement precision may be computed or measured.

1.8 This guide offers guidance for developing and reporting estimates of uncertainties in measurements made with gauges that have undergone calibration and verification.

1.9 All observed and calculated values shall conform to the guide for significant digits and rounding established in Practice D6026.

1.10 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. Within the text of this standard, SI units appear first followed by the inch-pound (or other non-SI) units in brackets.

1.10.1 Reporting of test results in units other than SI shall not be regarded as nonconformance with this guide.

1.11 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.

1.12 This guide offers an organized collection of information or a series of options and does not recommend specific course of action. This document cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this guide may be applicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which the adequacy of a given professional service must be judged, nor should this document be applied without consideration of a project’s many unique aspects. The word “Standard” in the title of this document means only that the document has been approved through the ASTM consensus process.

1.13 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.