Use with a WET150 Meter
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Temperature
T
he thermistor in the WET150 is internal to the white body, so it can be
slow to equilibrate with the soil temperature. This can affect the EC
measurement accuracy as the conductivity of typical plant nutrients
changes by ~2% / °C. If for use as a portable sensor, use it
in well-
equilibrated environments
where the air temperature doesn’t differ
significantly from the soil/substrate temperature.
Temperature can be displayed in °C or °F.
Pore Water EC (ECp)
The EC (Electrical Conductivity) of the water in the soil pores is calculated
by applying the Hilhorst equation. This is a very useful approximation that
works exceptionally well with the WET150 because the sensor measures
permittivity and measured bulk electrical conductivity (ECb) in the same
sample volume at the same frequency (100MHz). The Hilhorst equation
ceases to be a good approximation when there is too little water present, so
the meter displays
“too dry” instead (typically at <12.5%, as in mineral soil)
ECp can be displayed in mS/m, mS/cm or μS/cm.
