Taking essential tree parameters before the installation

The following tools are also recommended to ensure a correct and successful installation of Sap Flow Meters, but they are not included in the SFM-SK1 Sap Flow Meter Installation Kit:

• BARK DEPTH GAUGE (SFM-BARK) to measure the depth of the outer and inner bark; allows for deciding if a section of the bark needs to be removed to ensure Outer thermistors are well within the sapwood xylem;
• DIAMETER TAPE (SFM-Diameter-5 or Diameter-2) to measure stem diameter at 1.3m height or at installation position; and
• WOOD BORER (SFM-Borer) to extract a wood core and determine the sap wood layer thickness.

Removing Bark – if necessary – to prepare the installation site

If it is needed to remove a section of the bark prior to installation, the following tools are also recommended (not included in SFM-SK1 installation kit):

• MALLET or a hammer
• CHISEL – 32mm, so it can match the size of the drill guide.

Please refer to Sap Flow Meter installation videos on ICT International YouTube channel for the suggested use of these tools for bark removal.

Drilling the holes for thermistor and heater installation

In drilling the holes for the three needles, it is recommended to use the following tools and implements (not included in SFM-SK1 installation kit):

• DREMEL DRILL (SFM-DR) with the right size collet (482 1/16″ Collet), or a slow drilling tool to use with the SFM-55 drill bits. Drilling speed must be slow at the beginning, to slightly increase only if necessary. Drilling must be slowly incremental (a few mm at a time).
• HIGH VACUUM GREASE to lubricate the tip of the drill each time before a new drilling is performed, and also to use when inserting the Sap Flow Meter needles in the drilled holes.
• MALE VELCRO STRIPS to clean the flutes of the drill bits after each and before performing a new drilling.

Insulation of installation site

After drilling the installation holes with the Dremel drill, inserting the Sap Flow Meter needles properly, securing and powering the logger, as well as after the instrument has been tested and correctly set up with the chosen logging interval, insulation of Sap Flow Meter needles should happen by using (other materials can be used – not included in SFM-SK1 installation kit):

• KIMWIPES to fold on the long side 2 or three times, and then wrap it around the bottom of the three SFM1 needles;
• ALUMINIUM FOIL again to fold on the long side to have a slightly thicker section than the kimwipe, and then to wrap on top of the kimwipe again around the SFM1 needles

NOTE: SFM1x logger does not require insulation, whereas it is preferable to insulate SFM1 or PSY1 loggers with at least a layer of aluminium foil, to reflect sunlight and heat.

The HRM Sap Flux Meter Test Block

The HRM Sap Flow Meter Test Block is a functional verification standard for use with the HRM Sap Flow Meter. It is designed using a thermal compound of known thermodynamic properties and encased in a housing of known dimensions.

The needle spacing’s are asymmetrically arranged (which is a divergence from the Heat Ratio principle) to induce an artificial Heat Pulse Velocity. Each block is designed to induce an artificial velocity of approximately 18 cm hr or a mid range value of expected sap velocities as measured by the HRM in many species.

Depending upon the temperature conditions under which the block is used the heat dissipation from the block will be higher or lower which will ultimately impact the measured heat ratio causing a small divergence from the expected 18 cm/hr value.

The Test Block is not intended to be used as a calibration device rather as a known standard for operational verification of the Sap Flow Meter. This can be done in the lab as a pre deployment check before taking the equipment to the field and installation.

This will ensure correct functioning of the two measurement needles and the heater providing confidence in the operation of the equipment and subsequent results obtained, which will aid in data interpretation.

Test Block Error Codes

• 19.19 – No heater current was detected, therefore no heat pulse could be fired.
• 20.20 – Sap Velocity (Vs) was not calculated because the temperature rise of one of the thermistors was below the cut-off threshold.
• 21.21 – Sap velocity (Vs) could not be calculated because the temperature rise of one of the thermistors was negative.
• 22.22 Calculated Sap velocity (Vs) is less than the maximum practical physiological limit of reverse sap flow.

Additional useful tools for the installation of the Sap Flow Meter (not included in SFM-SK1 installation kit) are:

• WIRE CUTTER to cut solar panel cable if needed;
• LONG NOSE PLIERS to easily open the logger bus plugs for solar panel cable insertion. Useful also for extracting SD card, if needed

• LEVER TOOL (SFM-LT) in case you need to uninstall/extract the SFM1 needles from the installation site. Reduces the risk of damage to the needles (recommended: Pry Bar Flat 177mm (7″))

Lastly, if you require to move the sap flow meters to multiple trees, we suggest the use of:

• SFM-170 1.7mm DRILL BITS for drilling slightly bigger diameter wholes for the insertion of the stainless-steel sleeves
• Stainless steel SLEEVES (SFM-SL, pack of three), to insert permanently in the holes drilled with SFM-170. It is not possible to retrieve the sleeves from the installation site, but it allows easier reinstallation of the sap flow meter on the same spot.

Of course, do not forget to bring with you some spare straps or pull tie downs, to secure the Sap Flow Meter logger on the stem or branch and a laptop with the relevant CIS software for the instrument configuration.

For additional tips and correct installation procedures, please refer to the installation videos in ICT International’s website, or email sales@ictinternational.com.au

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