A transient heat probe sensor for measuring transpiration in the stem of woody plants.

Persistent Link:
http://hdl.handle.net/10150/184969
Title:
A transient heat probe sensor for measuring transpiration in the stem of woody plants.
Author:
Gomide, Reinaldo Lucio.
Issue Date:
1990
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
A compact portable electronic system has been developed for measurement of sap flow through the xylem in the stem of woody plants. This system utilizes a single heated thermistor probe which is alternately and automatically switched between a constant (heating phase) and a variable (cooling phase) temperature mode of operation. Experiments reported here have been carried out in two distinct porous medium, packed bands and the stem of several apple trees. The system performance was tested to detect the variations in flow rate. In both mediums, results indicated that the single heated thermistor is able to work as flowmeter since its transient thermal response was affected by the local fluid flow. The natural logarithm of the fractional response of the thermistor probe indicated that the system can not be analysed as a first order model. Non-linear regression analysis showed that the relationship between the probe sensor temperature response and the time elapsed from the beginning of cooling phase is adequately fitted by an additive exponential model. A dimensionless heat transfer analysis, applied to the thermistor probe, is outlined. Problems encountered in the transient heat transfer analysis are reported.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Engineering
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Agricultural Engineering; Graduate College
Degree Grantor:
University of Arizona

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleA transient heat probe sensor for measuring transpiration in the stem of woody plants.en_US
dc.creatorGomide, Reinaldo Lucio.en_US
dc.contributor.authorGomide, Reinaldo Lucio.en_US
dc.date.issued1990en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractA compact portable electronic system has been developed for measurement of sap flow through the xylem in the stem of woody plants. This system utilizes a single heated thermistor probe which is alternately and automatically switched between a constant (heating phase) and a variable (cooling phase) temperature mode of operation. Experiments reported here have been carried out in two distinct porous medium, packed bands and the stem of several apple trees. The system performance was tested to detect the variations in flow rate. In both mediums, results indicated that the single heated thermistor is able to work as flowmeter since its transient thermal response was affected by the local fluid flow. The natural logarithm of the fractional response of the thermistor probe indicated that the system can not be analysed as a first order model. Non-linear regression analysis showed that the relationship between the probe sensor temperature response and the time elapsed from the beginning of cooling phase is adequately fitted by an additive exponential model. A dimensionless heat transfer analysis, applied to the thermistor probe, is outlined. Problems encountered in the transient heat transfer analysis are reported.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectEngineeringen_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineAgricultural Engineeringen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.identifier.proquest9022107en_US
dc.identifier.oclc706817422en_US
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