Lynne Wong's PhD thesis

After measuring the EMC of dry corn stalk skin and stalk pith separately, Igathinathane et
al. (2005) proposed that the corn stalk EMC could be estimated from the sum of the dry
mass fraction and the measured EMC of each of the components, stalk skin and stalk pith,
as mentioned in Section 4.7.4.
5.5 METHODS FOR MEASURING EQUILIBRIUM MOISTURE CONTENT
Rouquerol et al. (1999) described methods to determine the equilibrium moisture content
of dry material by making use of one of three physical properties: pressure, gas flow or
mass in an environment of constant temperature and constant relative humidity.
In gas adsorption manometry, the pressure of the gas is measured in a calibrated, constant
volume environment, at a known temperature.
In gas flow techniques, a gas flowmeter is used to determine the amount adsorbed. The
flowmeter can be of a differential type (Nelsen and Eggertsen, 1958) or a simple form with
either a sonic nozzle (Rouquerol, 1972; and Grillet et al., 1977) or a thermal detector,
which emits a signal depending on the heat capacity, thermal conductivity or the mass flow
of the gas (Pieters and Gates, 1984).
In gas adsorption gravimetry as used by McBain and Bakr (1926), a spring balance is
utilised to measure the mass adsorbed. The apparatus consists of an adsorbent bucket
attached to the lower end of a fused silica spring, suspended within a vertical glass tube,
connected to a mercury manometer as shown below in Fig 5.3.
184