Preparing a Site
Woody stems are preferred, but this technique works on most herbaceous
species.
Expose a suitable area of water conducting xylem tissue or sap wood
(approximately 3cm x 1cm) to ensure that the psychrometer chamber well
will be completely covered by the sample. Remove the bark, phloem and
cambium layers, using a single edged razor blade to scrape a flat area of
xylem upon which to mount the psychrometer. Be very careful to maintain a
level plain to prevent producing a concave or convex surface.
Ensure that the surface is flat and there are no small gaps between the
psychrometer chamber and the xylem surface.
Thoroughly clean the area with distilled water and wipe dry. It is important to
the success of the installation that all living tissue is removed and no free
water is left on the xylem surface.
