scholarly journals Sap flow measurement by a single thermal dissipation probe: exploring the transient regime

2009 ◽  
Vol 66 (6) ◽  
pp. 608-608 ◽  
Author(s):  
Imen Mahjoub ◽  
Mohamed M. Masmoudi ◽  
Jean P. Lhomme ◽  
Netij Mechlia
Keyword(s):  
Sap Flow ◽  
Flow Measurement ◽  
Transient Regime ◽  
Thermal Dissipation ◽  
Thermal Dissipation Probe

scholarly journals Transient thermal dissipation method of xylem sap flow measurement: multi-species calibration and field evaluation

2009 ◽  
Vol 30 (1) ◽  
pp. 139-148 ◽  
Author(s):  
S. Isarangkool Na Ayutthaya ◽  
F.C. Do ◽  
K. Pannengpetch ◽  
J. Junjittakarn ◽  
J.-L. Maeght ◽  
...  
Keyword(s):  
Sap Flow ◽  
Flow Measurement ◽  
Xylem Sap ◽  
Field Evaluation ◽  
Thermal Dissipation ◽  
Xylem Sap Flow ◽  
Transient Thermal

Potential Sources of Errors in Estimating Plant Sap Flow Using Commercial Thermal Dissipation Probes

2018 ◽  
Vol 34 (6) ◽  
pp. 899-906
Author(s):  
Azadeh Alizadeh ◽  
Arash Toudeshki ◽  
Reza Ehsani ◽  
Kati Migliaccio
Keyword(s):  
Sap Flow ◽  
Thermal Gradient ◽  
Thermal Contact ◽  
Nonlinear Function ◽  
Conventional Technique ◽  
Thermal Dissipation ◽  
Cold Junction ◽  
Thermal Dissipation Probe ◽  
Thermal Difference ◽  
Plant Sap

Thermal dissipation systems are a conventional technique to estimate sap velocity by determining the temperature difference between sap flow probes. The Thermal Dissipation Probe (TDP) method is commercially available and has been used by many researchers and professionals to estimate sap flow in plants. However, some errors and practical issues cause inaccuracy when evaluating plant sap velocity with this technique. Specifically, the sources of these errors are from the effect of the ambient thermal gradient (i.e., error caused by the cold junction location), the underestimation of nighttime sap flow, and the deficient thermal contact between the probe and tree body. This article focuses on errors associated with the traditional TDP, which effect on the thermal difference between the reference and heated probes. These errors vary as a nonlinear function of the transmitter length and the numbers of cold junctions which are affected by changes in the ambient temperature. Keywords: Ambient thermal gradient, Sap velocity, Thermal dissipation probe (TDP), Thermocouple cold junction.

scholarly journals Estimation of transpiration of the 'Valencia' orange young plant using thermal dissipation probe method

2012 ◽  
Vol 32 (3) ◽  
pp. 573-581 ◽  
Author(s):  
Rubens D. Coelho ◽  
Lucas M. Vellame ◽  
Eusímio F. Fraga Júnior
Keyword(s):  
Sap Flow ◽  
Polynomial Regression ◽  
Probe Method ◽  
Thermal Dissipation ◽  
Angular Coefficient ◽  
Absolute Deviation ◽  
Valencia Orange ◽  
Thermal Dissipation Probe ◽  
Daily Transpiration ◽  
Outside Diameter

Most studies on measures of transpiration of plants, especially woody fruit, relies on methods of heat supply in the trunk. This study aimed to calibrate the Thermal Dissipation Probe Method (TDP) to estimate the transpiration, study the effects of natural thermal gradients and determine the relation between outside diameter and area of xylem in 'Valencia' orange young plants. TDP were installed in 40 orange plants of 15 months old, planted in boxes of 500 L, in a greenhouse. It was tested the correction of the natural thermal differences (DTN) for the estimation based on two unheated probes. The area of the conductive section was related to the outside diameter of the stem by means of polynomial regression. The equation for estimation of sap flow was calibrated having as standard lysimeter measures of a representative plant. The angular coefficient of the equation for estimating sap flow was adjusted by minimizing the absolute deviation between the sap flow and daily transpiration measured by lysimeter. Based on these results, it was concluded that the method of TDP, adjusting the original calibration and correction of the DTN, was effective in transpiration assessment.

Ozone uptake by adult urban trees based on sap flow measurement

2012 ◽  
Vol 162 ◽  
pp. 275-286 ◽  
Author(s):  
Hua Wang ◽  
Weiqi Zhou ◽  
Xiaoke Wang ◽  
Fuyuan Gao ◽  
Hua Zheng ◽  
...  
Keyword(s):  
Sap Flow ◽  
Flow Measurement ◽  
Urban Trees ◽  
Ozone Uptake
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