AccuPAR LP-80
8
CONFIG MENU
8.1
Calibration
The LP-80 has a calibrated external PAR sensor that it uses for
making simultaneous above and below canopy PAR measurements.
The LP-80 also uses this sensor to calibrate the AccuPAR probe,
ensuring that the PAR response between the external sensor and the
probe are the same. When you select this option, the Calibration
screen appears.
For best results, attach the external PAR sensor to the LP-80 by
inserting the bolt attached to the external sensor through the hole in
the bubble level. This will ensure that the sensor and probe are both
level. The directions state to level the probe and sensor, however
you can also calibrate the AccuPAR on a flat board or platform that
you can prop up at an angle to get more direct light from the sun.
The PAR level must be above 600
µ
mols m
−
1
s
−
1
. Values below
this will not update the calibration, so check the PAR levels before
proceeding with the calibration. In general, a clear day where the
sun is visible will be above 600
µ
mols. Overcast days are typically
less than 600
µ
mols.
When you have the instrument ready to calibrate, move out of the
probe area to minimize reflection off your body, and press the EN-
TER button to perform the calibration (it is important not to affect
light levels on the probe through shading or reflection). The current
probe calibration displays graphically. If you have no external sensor
attached while performing the calibration, the calibration will return
an error.
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