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How does the GrassMaster Pro work?
The capacitance measurement system
The capacitance probe method of pasture measurement works by measuring changes in
external capacitance using a circuit inside the probe. The more grass there is near the
probe, the more the capacitance is influenced. The indicator processes this data and
converts it into kilograms per hectare of dry matter.
The GrassMaster Pro has several built-in features to compensate for, and minimise the
effects of, different pasture characteristics like internal pasture moisture (dry matter
content), external pasture moisture (dew, rain), pasture morphology (leaves or stalks),
ambient temperature and relative humidity, and even ground soil moisture. The GM Pro
generates the CMR (Corrected Meter Reading) and uses it in a simple linear equation. The
CMR value can also be used in a multiple regression equation.
The capacitance probe system of measurement allows for these variations because the
capacitance technique effectively measures the volume of pasture, not just its surface area
or height. It does this by measuring the overall water mass near the probe, utilising the high
dielectric constant of water.
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GrassMaster Pro User Guide