Compensated heat pulse method.
Applications:
Sap flow sensors are used to measure the transpiration rates of trees. They determine orchard and plantation water requirements and irrigation times, water use by woody components of agroforestry systems, and water use by trees in forested watersheds. An installation typically has 2 to 3 sensors per tree with sensors in several adjacent trees.
Monitoring water use in irrigated orchards.
Scheduling irrigation in orchards.
Estimating water use by trees in agroforestry.
Monitoring species specific water requirements of trees.
http://www.solfranc.com/productos/wp-content/uploads/2014/11/