
80-11Humidity and Moisture Measurement
80.2.9 Measurement of Thermal Conductivity
e thermal conductivity of a material is related to the amount of water it contains. Heat pulses are sup-
plied
by a ne
edle
pr
obe,
an
d
th
e
co
oling
of th
e
ne
edle
a
er
en
ding
th
e
pu
lse
is me
asured
. It is a sim
ple
an
d
i
nexpensive
m
ethod
t
hat
n
eeds
c
alibration
f
or
t
he
m
aterial
i
n
w
hich
i
t
i
s
g
oing
to b
e
u
sed
.
80.2.10 Water Activity or Equilibrium Relative Humidity
A material enclosed in a measuring chamber is, aer some time, in equilibrium with its environment.
e mo
isture
co
ntent
of th
e
ma
terial
ca
n
be de
rived
fr
om
th
e
so
-called
ad
sorption
is
otherms
fo
r
th
at
sp
e- ...