SF-L Sap Flow Sensor
Continuous monitoring of sap flow in trees Improved "well known" Granier Sap Flow Sensor Accurate measurement of night-time sap flow Enhanced accuracy and reliability Simplified data processing Complete installation tools
Introduction The well known Granier sap flow sensor i.e. thermal dissipation probe (Granier, 1985 uses heat as a tracer of sap flow. Due to its simplicity, reliability and affordability, severa scientists have used the Granier technique all over the world. However, the technique has always had some shortcomings, which include: Granier technique determines arbitrarily the sap flow to a zero value every night. This contravenes the possibility of nighttime transpiration (Granier, 1987) and the fact of refilling process of tree body during the night.(Do and Rocheteau, 2002) The technique ignores the effect of natural temperature gradients of the sap-wood being measured, which range between +/- 1.5 C (fig. 1) and can cause considerable error in the results (DO and Rocheteau, 2002)
Technical Specifications Sensor composition: 2 needles
Needle size: 33 mm length, 1.5 mm diameter
Heating zone: 20 mm from top of the needle
Cable length: 0.7 m, extendable to 20 m
Tree size : Diameter>5 cm
Power consumption: 0.2 W +/-5%, 84 mA DC, stabilized
Output: 100 μV to 800 μV DC
Logger requirement: 1 differential channels
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