Level of state of People's Republic of China
Of plywood moisture content determine
Plywood - Determination Of Moisture Content

The measurement technique of the moisture content of the plywood that this standard set 1 main content and suitable scope to be defined by GB9846.2. This standard applies to the plywood that comprises by three-layer veneer at least, also apply to other all sorts of plywood.

2 cite term of plywood of standard GB 9846.2 and plywood of definition GB 9846.8 are common the feed of the test specimen of plywood of draw-out method GB 9846.9 of plywood

3 instruments

3.1 balance of   , reading is 0.01g accurately.

3.2 air of   convection sweatbox, each bits of temperature inside box can maintain 103 ± 2 ℃ .

3.3 desiccator of   , make with desiccative the air inside desiccator approachs absolutely dry state as far as possible.

4 sample and test specimen

The 4.1 regulations that press GB 9846.8 smoke   sampling board.

  the 4.2 formulary feed test specimen that press GB 9846.9.

4.3 test specimen of   can the whole cross section of delegate board, the part should be not contained on test specimen child, the blemish such as knothole and aperture, should crack loose on cleared test specimen piece with sawdust.

5 programs

Metage of 5.1 test specimen should with sampling the coequal condition when undertakes, come accurately 0.01g. Note: Should be in after sampling instantly feed test specimen undertakes first time metage. If cannot be accomplished, should adopt precautionary measures, avoid from sample embedded water rate produces change during metage.

5.2 test specimen are in 2 ℃ of 103 ± . below temperature dry arrive constant quality. Should notice not sweatbox crowded, when the test specimen in sweatbox approachs final metage state, do not put new test specimen again. Note: When the metage result when 2h of interval of test specimen around differs to not be more than 0.01g, can think to achieve constant quality.

After 5.3 test specimen of  are cooling in desiccator, precision metage is narrated before be being pressed quickly. Should prevent metage not seasonable and cause moisture content to increase more than 0.1% .

Calculate and express of 6 tests result

 the 6.1 moisture content that show test specimen with absolutely moisture content, press type is calculated, arrive accurately 0.1% . In 100 type of × of O of M of ／ of O) of M of H- of H =(M: H, the absolutely moisture content of test specimen, ％ : M H, the quality when test specimen samples, g; M O, the quality after test specimen is dry, g.

  the 6.2 one arithmetical average that a certain number of Zhang Ban's moisture content are equal to Zhang Huo to concern test specimen moisture content entirely, this value should arrive accurately 0.1% .
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