Determining the Moisture Content of Soil and Rock by Mass (Conventional Oven Method) - Soil Properties: Testing, Measurement, and Evaluation - page 44

and/or its being heated. Determine the mass of the container and
oven-dried specimen using the same type/capacity balance used in
(3). Record this value. Tight-fitting lids shall be used if it appears
that the specimen is absorbing moisture from the air prior to
determination of its dry mass.

(5.1) Cooling in a desiccator is acceptable in place of tight-fitting
lids since it greatly reduces absorption of moisture from the atmo-
sphere during cooling.

DATA

Data collected in this test should include the following:

Mass of container, M c
Mass of container and wet specimen, M cws
Mass of container and oven-dried specimen, M cs

Calculate the water content of the material as follows:

M w
M s

w M cws M cs M cs M c 100 100 (4-2)

31 2>1 24

where:
w = water content, %
M cws = mass of container and wet specimen, g
M cs = mass of container and oven-dried specimen, g
M c = mass of container, g
M w = mass of water ( M w = M cws - M cs ), g
M s = mass of solid particles ( M s = M cs - M c ), g

A laboratory test was conducted according to the procedure described
previously. The following data were obtained:

NUMERICAL
EXAMPLE

Mass of container, M c 59.85 g

Mass of container and wet specimen, M cws 241.25 g

Mass of container and oven - dried soil, M cs 215.43 g

Note: The data above are shown in boldface type to differentiate them
from other values that are not collected during the test. In other words,
boldface numbers indicate data collected during the test; all other num-
bers appear in regular type. This distinction is observed in the numeri-
cal examples throughout this topic.

M w M cws M cs

M w 241.25 215.43 25.82 g

M s M cs M c

M s 215.43 59.85 155.58 g