THB method with variable power Input for stem increment sensor Built-in datalogger No overheating of stem tissues Battery operated Low energy consumption Manufactured by EMS

Variable power
Constant temperature difference: 1, 2, or 3K
No overheating of stem tissues
Output in [kg/h] per tree independent on radial sap flow profile
Input for stem increment sensor
Built-in datalogger

EMS 81 is the most recent version of sap flow system based on a tissue heat balance (THB) method. Since 1973 when it was established, the instrumentation was seriously upgraded and theoretical background was developed and verified. The biggest advantage of this approach is direct heating of relatively large volume of xylem which brings high accuracy of the sap flow estimation. The measuring unit is quite sophisticated and therefore also expensive but the underlying theory is clear, without any uncertain empirical parameters (Tatarinov et al. 2005) and without any need for field calibration. Latest system EMS 81 enables connection of the sensor for continuous measurement of stem increment. This additional device synergistically increases the value of measured data (i.e. indirect estimation of the stem water potential, calculation of water use efficiency). Measuring system consists of the MicroSet 8X controlling unit, sap flow sensor SF 81, set of stainless electrodes, weather shields and connecting cables.

For more info:

pdf Data sheet
pdf User’s manual
pdf Installation guide