ASTM D6782-13
(Test Method)Standard Test Methods for Standardization and Calibration of In-Line Dry Lumber Moisture Meters
Standard Test Methods for Standardization and Calibration of In-Line Dry Lumber Moisture Meters
SIGNIFICANCE AND USE
4.1 In-line meters provide a rapid means of detecting moisture content of lumber or wood products in processing (that is, on a continuous production line). Two major uses are monitoring the performance of the drying process (air drying, kiln drying), and providing sorting or identification of material at predetermined levels of moisture content. These measurements are inferential in the sense that physical measurements are made and compared against calibration curves to obtain an indirect measure of moisture content. These measurements may be influenced by one or more physical properties such as actual moisture content (average and gradient; see Appendix X5), density, surface moisture, chemical composition, size, and temperature of wood. In addition, the measurements may also be influenced by environmental conditions and the design specifications of the meter. The best performance is obtained by an awareness of the effect of each parameter on the meter output and correction of readings as specified by these test methods.
4.2 The two major anticipated users of these test methods are instrument manufacturers whose primary concern is laboratory standardization and calibration, and instrument owners who may have a primary focus on field standardization and calibration. These test methods present the laboratory and the field as separate tracks (see Appendix X2).
4.2.1 Laboratory Standardization and Calibration—This portion of these test methods is intended for guidance of equipment manufacturers. Specific test recommendations are tailored to the capabilities of a laboratory environment.
4.2.2 Field Standardization and Calibration—The predominant use of in-line meters is in production in which lumber characteristics and environmental conditions reflect actual mill processes. Field standardization and calibration is essential to address or encompass much of the variability in production.
4.2.3 Applications using the output of the in-line moisture meter may modi...
SCOPE
1.1 These test methods apply to instruments designed to detect, or measure, moisture in wood which has been dried below the fiber saturation point. The purpose of these tests is to provide a unified standard against which such systems can demonstrate their suitability for their intended use (see Appendix X1).
1.1.1 Sensitivity to thin layers of surface moisture such as caused by dew or brief rain exposure is not addressed by these methods. Applications, such as screening material for surface adhesion, may require additional assessment methodology and criteria (see Appendix X5).
1.2 The standard is configured to support tests by moisture meter manufacturers as well as end-users of such systems, therefore the text follows two tracks (see Appendix X2).
1.3 Test methods specified for manufacturers are generally designed for laboratory settings and are intended to provide a standard against which a manufacturer certifies calibration and general system conformance.
1.4 Test methods for end-users are generally designed for field settings and are intended as a standardized set of procedures for determining the suitability of a specific machine for a particular use.
1.5 Applications such as lumber marking or sorting systems utilizing the output of the in-line meter are not part of this standard.
1.6 Applications requiring sensitivity to and identification of localized wet areas are limited to general recommendations. The presence of wet-spots is the subject of Appendix X8.
1.7 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.8 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.
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Designation: D6782 − 13
Standard Test Methods for
Standardization and Calibration of In-Line Dry Lumber
1
Moisture Meters
This standard is issued under the fixed designation D6782; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
1.1 These test methods apply to instruments designed to
bility of regulatory limitations prior to use.
detect, or measure, moisture in wood which has been dried
belowthefibersaturationpoint.Thepurposeofthesetestsisto
2. Referenced Documents
provide a unified standard against which such systems can
2
2.1 ASTM Standards:
demonstrate their suitability for their intended use (see Appen-
D1990 Practice for Establishing Allowable Properties for
dix X1).
Visually-Graded Dimension Lumber from In-Grade Tests
1.1.1 Sensitivity to thin layers of surface moisture such as
of Full-Size Specimens
caused by dew or brief rain exposure is not addressed by these
D2395 TestMethodsforDensityandSpecificGravity(Rela-
methods. Applications, such as screening material for surface
tive Density) of Wood and Wood-Based Materials
adhesion, may require additional assessment methodology and
D2915 Practice for Sampling and Data-Analysis for Struc-
criteria (see Appendix X5).
tural Wood and Wood-Based Products
1.2 The standard is configured to support tests by moisture
D4442 Test Methods for Direct Moisture Content Measure-
meter manufacturers as well as end-users of such systems,
ment of Wood and Wood-Based Materials
therefore the text follows two tracks (see Appendix X2).
D4444 Test Method for Laboratory Standardization and
Calibration of Hand-Held Moisture Meters
1.3 Test methods specified for manufacturers are generally
D4933 Guide for Moisture Conditioning of Wood and
designed for laboratory settings and are intended to provide a
Wood-Based Materials
standard against which a manufacturer certifies calibration and
D5536 PracticeforSamplingForestTreesforDetermination
general system conformance.
of Clear Wood Properties
1.4 Test methods for end-users are generally designed for
field settings and are intended as a standardized set of
3. Terminology
proceduresfordeterminingthesuitabilityofaspecificmachine
3.1 Definitions of Terms Specific to This Standard:
for a particular use.
3.1.1 accept/reject meters, n—meters that permit identifica-
1.5 Applications such as lumber marking or sorting systems tion or sorting, or both, of pieces into moisture content classes.
utilizing the output of the in-line meter are not part of this
The simplest design has one set point or target level to separate
standard. wetter from drier pieces. Often the meters described in 3.1.5
may be operated as accept/reject meters.
1.6 Applications requiring sensitivity to and identification
3.1.2 field, n—an environment usually not meeting the
of localized wet areas are limited to general recommendations.
The presence of wet-spots is the subject of Appendix X8. criteria of 3.1.4. This is often a meter installation at the wood
processing facility where the meter and the lumber are subject
1.7 The values stated in SI units are to be regarded as the
to the process environment of mill production.
standard. The values given in parentheses are for information
3.1.3 flow, n—a term that describes the movement and
only.
orientation of the piece with respect to the sensing area.
1.8 This standard does not purport to address all of the
3.1.3.1 longitudinal-flow—in this flow arrangement, pieces
safety concerns, if any, associated with its use. It is the
pass lengthwise through the sensing area. All or some portion
of the length may be sensed.
1
These test methods are under the jurisdiction of ASTM Committee D07 on
Wood and are the direct responsibility of Subcommittee D07.01 on Fundamental
2
Test Methods and Properties. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved April 1, 2013. Published May 2013. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 2002. Last previous edition approved in 2005 as D6782 - 05. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D6782-13. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
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D6782 − 13
3.1.3.2 transverse-flow—in this flow arrangement, the wood, localized obstructions to uniform drying or non-uniform
pieces pass cros
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it 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 version
of the standard as published by ASTM is to be considered the official document.
Designation: D6782 − 05 D6782 − 13
Standard Test Methods for
Standardization and Calibration of In-Line Dry Lumber
1
Moisture Meters
This standard is issued under the fixed designation D6782; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 These test methods apply to instruments designed to detect, or measure, moisture in wood which has been dried below the
fiber saturation point. The purpose of these tests is to provide a unified standard against which such systems can demonstrate their
suitability for their intended use (see Appendix X1).
1.1.1 Sensitivity to thin layers of surface moisture such as caused by dew or brief rain exposure is not addressed by these
methods. Applications, such as screening material for surface adhesion, may require additional assessment methodology and
criteria (see Appendix X5).
1.2 The standard is configured to support tests by moisture meter manufacturers as well as end-users of such systems, therefore
the text follows two tracks (see Appendix X2).
1.3 Test methods specified for manufacturers are generally designed for laboratory settings and are intended to provide a
standard against which a manufacturer certifies calibration and general system conformance.
1.4 Test methods for end-users are generally designed for field settings and are intended as a standardized set of procedures for
determining the suitability of a specific machine for a particular use.
1.5 Applications such as lumber marking or sorting systems utilizing the output of the in-line meter are not part of this standard.
1.6 Applications requiring sensitivity to and identification of localized wet areas are limited to general recommendations. The
presence of wet-spots is the subject of Appendix X8.
1.7 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.8 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.
2. Referenced Documents
2
2.1 ASTM Standards:
D1990 Practice for Establishing Allowable Properties for Visually-Graded Dimension Lumber from In-Grade Tests of Full-Size
Specimens
D2395 Test Methods for Specific Gravity of Wood and Wood-Based Materials
D2915 Practice for Sampling and Data-Analysis for Structural Wood and Wood-Based Products
D4442 Test Methods for Direct Moisture Content Measurement of Wood and Wood-Base Materials
D4444 Test Method for Laboratory Standardization and Calibration of Hand-Held Moisture Meters
D4933 Guide for Moisture Conditioning of Wood and Wood-Based Materials
D5536 Practice for Sampling Forest Trees for Determination of Clear Wood Properties
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
1
These test methods are under the jurisdiction of ASTM Committee D07 on Wood and are the direct responsibility of Subcommittee D07.01 on Fundamental Test Methods
and Properties.
Current edition approved Oct. 1, 2005April 1, 2013. Published October 2005May 2013. Originally approved in 2002. Last previous edition approved in 20042005 as
D6782 - 04.D6782 - 05. DOI: 10.1520/D6782-05.10.1520/D6782-13.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
D6782 − 13
3.1.1 accept/reject meters, n—meters that permit identification or sorting, or both, of pieces into moisture content classes. The
simplest design has one set point or target level to separate wetter from drier pieces. Often the meters described in 3.1.5 may be
operated as accept/reject meters.
3.1.2 field, n—an environment usually not meeting the criteria of 3.1.4. This is often a meter installation at the wood processing
facility where the meter and the lumber are subject to the process environment of mill production.
3.1.3 flow, n—a term that describes the movement and orien
...
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