Measuring the wood moisture of logs
13
6
Measuring the wood moisture of logs
The Wöhler HF 550 can measure the wood moisture of logs according to VDI 4206,
part 4. This measurement is based on a resistance measurement. In order to obtain an
exact measurement, the respective material is considered.
The wood moisture depends on the temperature of the material. For this reason, the
wood temperature must be measured at first. The meter will automatically perform a
temperature compensation afterwars.
NOTE!
For measuring the wood moisture of logs the Hammer Probe or the Lance Probe must
be connected to the meter.
6.1
Theoretical background
The resistance measurement uses the needles of the Hammer Probe or the Lance
Probe. The meter will automatically determine the wood moisture u. This is the water
mass m
w
bound in the fuel and related to the absolute dry fuel mass m
B
according to
equation (1):
𝑢 =
𝑚
𝑤
𝑚
𝐵
∙ 100%
Equation 1
Explanation:
u
= wood moisture
m
w
= water mass bound in the wood
m
b
= absolute dry fuel mass
NOTE!
According to the above equation the wood moisture may be higher than 100 %.
