Field Scout CM 1000, Руководство по эксплуатации продукта

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Like the ambient light sensors, the target leaf should
always be held perpendicular to the sun’s rays to
maximize light reflectance into the meter’s lens from the
leaf surface. All samples must be taken against the same
background. It is preferable to hold the leaf with one’s
hand, not having anything immediately behind the leaf. If
that is not practical, a flat black background should be
used behind the leaf samples. With light-colored or
glossy backgrounds, one may not only be sensing the
reflective properties of the leaf but also the reflective
properties of the background shining through the leaf.
It is preferable to sample with the leaf still attached to the
plant. The effect on light absorption or reflection due to
the extreme water stress of detached leaves is not known.
Canopy-level measurements are recommended for fine-
textured turf grass only . When making measurements on
turf grass, an adequate measuring procedure should
include having the sun, the target, and the meter in
approximately the same relationship with each other for
each reading. The problem with trying to measure an
entire plant canopy is that not all leaves in a coarse canopy
are exposed to the same ambient light. Because the light
reflected from a canopy is being reflected in many
different directions and that reflected light is being
compared to the available ambient light, it is absolutely
necessary for the both the entire sample area and the
ambient light sensors to be subjected to the same quantity
and quality of light.