ASTM D1102:84(R2021) pdf free download – Standard Test Method for Ash in Wood.
4. Test Specimen
4.1 The test specimen shall consist of approximately 2 g of wood that has been ground to pass a No. 40 (425-pm) sieve. Care shall be taken to ensure that it is representative of the entire lot of material being tested.
5. Procedure
5.1 Ignite the empty crucible and cover over a burner or in the muffle at 600°C, cool in a desiccator, and weigh to the nearest 0.1 mg. Place the 2-g test specimen in the crucible, determine the weight of crucible plus specimen, and place in the drying oven at 1(X) to 105°C with the crucible cover removed. After 1 h, replace the cover on the crucible, cool in a desiccator, and weigh. Repeat the drying and weighing until the weight is constant to within 0.1 mg. During the cooling and weighing periods, keep the crucible covered to prevent absorption of moisture from the air. Record the weight (crucible plus specimen minus weight of crucible) as the weight of the oven-dry test specimen.
5.2 Place the crucible and contents, with the cover removed, in the muffle furnace and ignite until all the carbon is eliminated. Heat slowly at the start to avoid flaming and protect the crucible from strong drafts at all times to avoid mechanical loss of test specimen. The recommended temperature of final ignition is 580 to 600°C. Avoid heating above this maximum.
5.3 Remove the crucible with its contents to a desiccator, replace the cover loosely, cool, and weigh accurately. Repeat the heating for 30-mm periods until the weight after cooling is constant to within 0.2 rng.
6. Calculations and Report
6.1 Calculate the percentage of ash, based on the weight of the moisture-free wood, as follows.