Linked Life Data

11542603

Source:http://linkedlifedata.com/resource/pubmed/id/11542603

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2000-2-26
pubmed:abstractText
Accurate measurement of the leaf to air temperature gradient is crucial for the determination of stomatal conductance and other plant responses in both single leaves and in plant canopies. This gradient is often less than 1 degree C, which means that leaf temperature must be known to within about +/- 0.1 degree C. This is a challenging task, but new, miniature infra-red transducers from Exergen Corporation (Newton, MA) and Everest Interscience (Tucson, AZ) can be modified and calibrated to achieve this accuracy. The sensors must be modified to add thermal mass and the Exergen sensor requires a measurement of sensor body temperature. Significant error is caused by the discharge of a capacitor in the standard Exergen sensor, but we tested it without the capacitor. The sensors respond rapidly to changes in target temperature, but require 2 to 10 minutes to respond to changes in sensor body temperature, which is often the largest source of error. A new, sensitive method for measuring field of view indicates substantial peripheral vision for both sensors and a wider field of view than specified by the manufacturers. Here we describe sensor output as a function of target and sensor body temperatures, and provide a generic (sensor independent) equation that can be used to achieve +/- 0.2 C accuracy with Exergen sensors. The equation was developed and verified using two black body calibrators.
pubmed:keyword
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
S
pubmed:status
MEDLINE
pubmed:issn
0273-1177
pubmed:author
pubmed:issnType
Print
pubmed:volume
22
pubmed:owner
NASA
pubmed:authorsComplete
Y
pubmed:pagination
1425-34
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Evaluation and modification of commercial infra-red transducers for leaf temperature measurement.
pubmed:affiliation
Dept. of Plants, Soils, Biometeorology, Utah State Univ, Logan 84322-4820, USA.
pubmed:publicationType
Journal Article, Comparative Study