inherent moisture

n

in coal, the moisture that exists as an integral part of the coal in its natural state, including water in pores, but not that present in macroscopically visible fractures.

DISCUSSION — In coal as it exists in the ground before it is disturbed, the pores are essentially filled with water (gases, for example, methane, may occupy a minor proportion of the pore volume in some coals); this pore-filling moisture is determined as total moisture and referred to as inherent moisture in a freshly collected sample that (1) does not exhibit visible water on fracture surfaces, (2) has not been allowed to dry after collection, and (3) was collected from a fresh coal face that is not dried (see Classification D388). On samples not meeting these criteria, inherent moisture may be estimated by determining equilibrium moisture in accordance with Test Method D1412. D388, D1412