GB/T 1930-2009Method for determination of the annual rings width and latewood rate of wood (English PDF)

Foreword

This standard replaces GB/T 1930-1991 "wood ring width and latewood rate determination method." this standard compared with GB/T 1930-1991 The main changes are as follows.

--- Average width in the range of "cross-section of each timber, and sooner or later the whole ring of the obvious difference between each whole timber wood rings in latewood the percent of each "to" complete transverse section of each timber and an average width of annual rings of wood obvious difference between morning and evening wood Complete ring in the percent of late wood ";

--- Referenced standard is "GB 1941 Wood hardness test" was changed to "GB/T 1928-2009 square wood physical and mechanical tests Law General "and" intercept method "GB/T 1929-2009 wood sawing wood physical and mechanical tests and samples;

--- The Chapter 5, "Sample" requirement was changed to "hardness of the sample using 5.1 or .5.2 specimen sample preparation using specially made to Check sum according to the provisions of GB/T 1928-2009 Chapter 3 will be ";

--- The 6.1 "at the end surface of the sample, according to a straight line radial" to "the specimen in the transverse plane, has been designated by the perpendicular to the radial ring Line ", delete the words" will fill the measurement results in Appendix A "requirements;

--- Detailed test requirements increase the preparation of the report, and accordingly made some changes to Appendix A.

Appendix A of this standard is a normative appendix.

This standard was proposed by the State Forestry Administration.

This standard by the National Standardization Technical Committee timber.

This standard was drafted. China Forestry Science Institute of Wood Industry.

Participated in the drafting of this standard. Chinese Academy of Forestry Forestry Institute for New Technologies.

1 Scope

This standard specifies the determination timber ring width and latewood rate test equipment, samples, test procedures and results of calculations.

This standard applies to the determination of the average width of the late wood in transverse section of each complete ring of material and sooner or later, obviously distinguish each complete ring of wood the percent of material.

2 Normative references

The following documents contain provisions which, through reference in this standard and become the standard terms. For dated references, subsequent Amendments (not including errata content) or revisions do not apply to this standard, however, encourage the parties to the agreement are based on research Whether the latest versions of these documents. For undated reference documents, the latest versions apply to this standard.

GB/T 1928-2009 physical and mechanical test methods - General GB/T 1929-2009 physical and mechanical test materials and test specimens sawing method Principle 3 all measurement sample of the total width of the entire ring, and the number of late wood to determine its average width and latewood ring rate.

4 Test Equipment

Measuring test, measurements should be accurate to 0.01mm.

5 Sample

5.1 or hardness of the sample using the sample using specially made.

5.2 Sample production requirements and inspections according to the provisions of GB/T 1928-2009 Chapter 3 performed.

6 Test procedure

6.1 specimen transverse plane, perpendicular to the radial ring by a straight line, along a straight line to determine a total width of the ring portion of the whole, accurate to 0.01mm, and count the number of rings in the measurement range.

6.2 in the range of the entire sample ring total width, measure the width of each ring of late wood, accurate to 0.01mm.

7 Results Calculation

(1) calculate the average width of 7.1 sample style rings shall be accurate to 0.1mm.

R = Chou Chou shape

Where.

--- R Chou average width of the specimen ring, in millimeters (mm);

The total width of the entire ring within the range of the measurement sample Chou --- millimeters (mm);

Integer number of ring-shaped inner --- measurement sample range is detected.

(2) the calculation formula should be 7.2 latewood percentage, to the nearest 1%.

Lw = sumL Chouchou × 100 (2)