Leaf Porometer Operator’s Manual
2. About the Leaf Porometer
4
2. About the Leaf Porometer
The Leaf Porometer is a battery-operated, menu-driven
device used to measure stomatal conductance of leaves. Sto-
matal conductance is a function of the density, size, and
degree of opening, of stomata, which are pores in plants
that open to the outside air. The Leaf Porometer measures
stomatal conductance by putting the conductance of a leaf
in series with two known conductance elements, and com-
paring the humidity measurements between them. It can
display information in three selectable units:
•
mmol/m
2
s
(millimoles per meter squared
seconds)
•
m
2
s/mol
(meters squared seconds per mole)
•
s/m
(seconds per meter)
The first is a unit of conductance, while the other two are
units of resistance. To change between them, use the arrow
keys when taking a reading (see “Making a Measurement,”
pp. 16). They can also be altered by using the Units screen
under the Configuration Menu.
Specifications
Operating Environments:
5 - 40
o
C; 0 - 90% relative
humidity (non-condensing).
NOTE: At temperatures less than
10° C, Automatic mode may experience errors, despite corrections
that have been made.
(See Chapter 3 more information about
Auto mode.)