The moisture contents drier than the sample as collected
were adjusted by adding water to the known amount of
oven dried samples. The moisture contents moister than
the collected sample were adjusted by adding water to
the known amount of material as collected. Each unit
of the OxiTop system consists of a 1 l jar, a pressure sensor-
data logger head (OxiTop-C WTW, Weiheim, Germany),
and a rubber capsule for NaOH pellets. As
oxygen is consumed, any CO2 produced is absorbed on
the NaOH pellets, leading to a pressure drop that is
directly related to the oxygen utilization. A controller
(OxiTop OC 110 WTW, Weiheim, Germany) is used to
collect data from the pressure sensor data loggers. Company
supported Software (Achat OC, PC communication
software version 2.03) is used to download the data from
the controller to a spreadsheet.