ICT International HFD8, Быстрый старт

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Again
,
a small amount of vacuum grease can be applied (using the offset 10 ml syringe) to
aid insertion. Using the
Insertion Tool
provided
, slowly
ease the sleeve into position. Never
force the sleeve and resist the temptation to “tap” the
Insertion Tool
to insert the sleeve.
Any force greater than finger pressure will buckle the very thin walled sleeve
,
destroying
the sleeve
and rendering it unable to be reused,
and potentially (if the sleeve can be
extracted) ruining the installation site
,
requiring a completely new site to be started
d
ue to
the hole
deforming during
extraction.
The measurement needles of the HFD Sap Flow Meter are made of hollow 1.6 mm stainless
steel tubing. They can easily be bent, damaged or broken off if basic care is not taken in
handling the instrument. The significant length of the needles relative to this very thin
diameter demand
s
additional attention to detail when handling or transporting the
needles. Once installed in sleeves within the tree the needles
are
very robust.
NOTE: the needles gain much of their structural strength when combined with the sleeves.
ICT provides sleeves with a closed end to prevent sap and resin from filling the sleeve and
gluing the needle in place. This also enables the sleeves to be left in place without the HFD
needles installed and to be used again at a later time without the sleeves having become
blocked by sap & resin.
NOTE : if
you
intended to use the sleeves for more than one growing season
,
it may be
advisable to allow a small excess of sleeve protruding from the stem surface to
compensate
for tree growth and increment of the stem, otherwise the sleeves will become
engulfed and obscured by the tree making reuse difficult. If this technique is employed it is
very important to make allowance for this to ensure the specific depths of insertion for the
measurement points are known and adjusted using a insulated spacer (see below).
Insert the sleeves into the drilled holes. A Sleeve set consists of
three 10
0mm long sleeves
for the
three
measurement needles and
one
1
2
0mm long sleeve for the heater needle. The
sleeves should slide easily into the drilled holes
.
7.3 Needle Position:
Positioning of the first measurement point is crucial to the interpretation of the measured
data.
All measurement needles have a 20mm distance between the base and the first
measurement point (Point 1). To accurately position this first or outer measurement point
,
a plastic spacer should be cut to the precise length and slid over the needle to regulate
the positioning of this measurement point.
Begin by measuring the bark thickness and establish a reference or datum point of smooth
,
firm
bark,
(not rough
,
flaky bark
)
s
uch
that the outer measurement point is located 5mm
below the cambium.
NOTE:
This depth of 5mm below the cambium is the default value used in
the
Sap Flow
Tool software for analysing the data.