Sayan Sdoodee, Chusak Limsakul and Naree Wongwongaree

pp. 177 - 188

Abstract

The prototype of a heat-pulse sapflow sensor (PSU-TTSF) was developed for continuous recording of
sapflow. The efficiency of the measurement of PSU-TTSF was evaluated by comparing with the Greenspan
Sapflow Sensor (a commercial equipment). The 10-year old longkong trees were used as the test plants. The
results showed that both equipments could be used for continuously automated records. The accuracy of the
measurement was evaluated, and it was found that the sap flow values measured by PSU-TTSF exhibited high
relationship with those values measured by Greenspan Sapflow Sensors. The sap flow measured by PSUTTSF tended to be lower, and the difference was approximately 16%. To reduce the error of measurement, the
method of installing PSU-TTSF probe set needs to be improved by using a drill guide.

Keywords

• Greenspan Sapflow Sensors
• heat-pulse sapflow sensors
• longkong trees
• PSU-TTSF
• sap flow