An improved sensor for precision detection of in situ stem water content using a frequency domain fringing capacitor
© European Union 2014. New Phytologist © 2014 New Phytologist Trust.
| Veröffentlicht in: | The New phytologist. - 1990. - 206(2015), 1 vom: 18. Apr., Seite 471-481 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2015
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| Zugriff auf das übergeordnete Werk: | The New phytologist |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't frequency-domain sensor nondestructive measurement of stem water content (StWC) plant water stress stem water storage volumetric water content Water 059QF0KO0R |
| Zusammenfassung: | © European Union 2014. New Phytologist © 2014 New Phytologist Trust. One role of stems is that of water storage. The water content of stems increases and decreases as xylem water potential increases and decreases, respectively. Hence, a nondestructive method to measure stem water content (StWC) = (volume of water) : (volume of stem), could be useful in monitoring the drought stress status of plants. We introduce a frequency domain inner fringing capacitor-sensor for measuring StWC which operates at 100 MHz frequency. The capacitor-sensor consists of two wave guides (5-mm-wide braided metal) that snugly fit around the surface of a stem with a spacing of 4-5 mm between guides. Laboratory measurements on analog stems reveals that the DC signal output responds linearly to the relative dielectric constant of the analog stem, is most sensitive to water content between the waveguides to a depth of c. 3 mm from the stem surface, and calibrations based on the gravimetric water loss of excised stems of plants revealed a resolution in StWC of < ± 0.001 v/ v. The sensor performed very well on whole plants with a 100-fold increased resolution compared with previous frequency domain and time domain reflectometry methods and, hence, may be very useful for future research requiring nondestructive measurements of whole plants |
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| Beschreibung: | Date Completed 11.02.2016 Date Revised 09.11.2020 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1469-8137 |
| DOI: | 10.1111/nph.13157 |