Its about different methods of measuring Moisture xcontent.

1. Measurement
of
Moisture Content

2. Moisture Content
It is the quantity of water contained in a material. Like
soil (soil moisture), rock, ceramics and wood.
Moisture content is used in a wide range of scientific and technical
areas. Like smart irrigation, ground water studies, soil chemistry etc.
 Moisture content is expressed as a ratio, which can range from 0
(completely dry) to the value of the materials' porosity at
saturation.
Moisture content can be given on a volumetric or mass (gravimetric)
basis.

3. Calculation of Moisture Content
Moisture content(θ) is calculated either on volumetric basis:
= Volume of water and is the
total volume (that is soil volume + water volume + air space).
Or it is calculated on mass (gravimetric basic):
Where is the mass of water and is the bulk mass.

4. Methods for measurement of Moisture Content
1.Direct Methods
2.Laboratory methods
3.Geophysical methods
4.Satellite remote sensing method

5. 1. Direct Methods
Water content can be directly measured using a known volume of the material, and a
drying oven. Volumetric water content, θ, is calculatedusing:
Where,

6. 1. Direct Methods (Cont…)
For materials that change in volume with
water content, such as coal, the water
content, u, is expressed in terms of the mass
of water per unit mass of the moist specimen:

7. 2. Laboratory Methods
These methods which determine moisture content of a sample
include chemical titrations (for example the Karl Fischer titration),
determining mass loss on heating (perhaps in the presence of an
inert gas), or after freeze drying.

8. 3. Geo-physical Methods
There are several geophysical methods available that can approximate in situ(in
place) soil water content:
1. Time-domain reflectometry (TDR),
2. Neutron probe,
3. Frequency domain sensor,
4. Capacitance probe,
5. Amplitude domain reflectometry,
6. Electrical resistivity tomography
7. Ground penetrating radar (GPR)

9. 4. Satellite remote sensing Method
Satellite microwave remote sensing is used to estimate soil
moisture based on the large contrast between the dielectric
properties of wet and dry soil.
The microwave radiation is not sensitive to atmospheric variables,
and can penetrate through clouds.
Also, microwave signal can penetrate, to a certain extent, the
vegetation canopy and retrieve information from ground surface .
The data from microwave remote sensing satellite such as:
WindSat, AMSR-E, RADARSAT, ERS-1-2, Metop/ASCAT are used to
estimate surface soil moisture.