Leaf Porometer Operator’s Manual
4. Sensor Head Calibration
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5) Sensor Offset/Stability
The sensors must give similar humidity readings for accu-
rate stomatal conductance measurements. Before begin-
ning a calibration, the leaf porometer checks to make sure
that the two sensors in the sensor head agree well with each
other. For the sensors to agree, the air in the diffusion path
should be well mixed.
Holding the Sensor Head
Holding the sensor head in the correct manner is very
important. If held incorrecly, water vapor from your fingers
can expose the Teflon disk to artificially high humidity and
cause inaccurate readings. The pictures below illustrate the
correct way to hold the external sensor.
Correct Incorrect