SF-L, Improved Granier sensor with four needles and a much higher accuracy
Sap Flow Sensors
Sap Flow sensors measure the continuous rate of water uptake in trees. They consist of at least two temperature sensors, inserted into the tree one above the other
SF-G Granier Type 2-Needle Sensor
This sensor uses the standard Granier method to caclulate sap flow. It can be used for any tree diameter >2cm.
SF-L Improved 4-Needle sensor
The standard 2-needle sensor can have temperature inaccuracies due to temperature gradients within the sap-wood. The SF-L sensor has 2 additional sensors which measures and accounts for these variations. Resulting sap flow measurements are significantly more accurate and the important reference point of zero sap flow (ΔTmax) remains stable over long periods. When used in conjunction with dendrometer readings extremely accurate day & night time determinations can be made.
This sensor is not suitable for tree diameters <8cm and requires 3 x differential datalogger channels.
Ecomatik have been manufacturing precision instruments to monitor plant growth and water use for over 20 years. Based in Germany, they supply researchers in over 60 countries through a network of approved distributors.