Patent ID: 8590373

Claim:
A portable sensing apparatus for measuring sap flow in a stem region of a plant, and electrically interconnected with dataloggers for monitoring electrical signals functionally related to said sap flow in said plant, said portable sensing apparatus comprising: a flexible substrate having embedded therein an electronics assembly comprising a first pair of temperature-sensing devices and a second pair of temperature-sensing devices, and a thermopile with a heating strip also embedded therein and disposed between said first pair of temperature-sensing devices and said second pair of temperature-sensing devices; said first pair of temperature-sensing devices disposed above said thermopile heating strip and said second pair of temperature-sensing devices disposed below said thermopile heating strip, and said first pair of temperature-sensing devices and said second pair of temperature-sensing devices electrically arranged in parallel, thereby automatically averaging two signals, with each said signal generated from each of two said pairs of temperature-sensing devices, into 1 dT temperature value; and said thermopile disposed longitudinally of said flexible substrate and having a plurality of temperature-sensing devices electrically interconnected in series for generating a signal responsive to all conduction energy losses as sap flows through said stem region of said plant, and for calculating sap flow rate from a simplified energy balance formula wherein all said conduction energy losses are grouped together into a single conduction value and heat from said conductivity is functionally related solely to radial power engendered by said heating strip.