56
MOISTURE
Moisture Gauge Calibration
F
E
C
O
U
N
T
R
A
T
I
O
The count rate is ratioed to a standard count and a suitable equation is:
CR = E + F * M
Where:
CR = Count Ratio
M = Moisture content
E = CR at zero moisture content
F = Slope of the function
In order to determine the values of E and F, two moisture standards are
required. One may be zero since it is easy to obtain and the other must
have a known amount of water or contain hydrogen, which can be related to
water.
The moisture measurement is sometimes called backscatter but once a
neutron has been thermalized by multiple collisions with hydrogen, it obeys
gas diffusion laws and drifts off in any direction. Some arrive at the detector
and get counted.
