ASAE Standards for Moisture Determination

Many professional societies such as ASAE, the American Oil Chemists' Society (AOAC), and the American Assocation of Cereal Chemists (AACC) have published standard procedures for oven moisture determinations. Four separate standard procedures are listed in ASAE Standards (1995).

ASAE Standard S352.2 (DEC 92) - Moisture Measurement - Unground Grain and Seeds

This standard gives a procedure for determining the moisture of whole grain kernels and seeds. The equipment used in this procedure include: a numbered dish made of heavy gauge aluminum with a tight fitting cover, a balance with an accuracy of 0.001g, a desiccator that is airtight and contains a suitable desiccant, and a forced-draft or gravity convection oven. The oven should be well insulated, maintain uniform heating inside the oven, and be accurate to ±0.5°C.

The aluminum dishes are dried for 1 hour at the test temperature and subsequently weighed to determine the tare weight. A 15g or larger sample of grain or seed is placed in the dish, the dish is covered and reweighed. The dish is then uncovered and placed with its cover in the oven for a heating period and temperature indicated in the table included in the standard. For grains and seeds with moistures greater than 25%, the variability of the results can be reduced by using larger cans and 100g samples. At the completion of the heating period, the lids are placed on the cans and the cans are placed in a desiccator to cool to room temperature. They are then weighed and the moisture content is calculated using one of the equations mentioned earlier.