title: A root moisture sensor for plants in microgravity.
abstract: Development of components for bioregenerative life-support systems is a vital step toward long-term space exploration. The culturing of plants in a microgravity environment may be optimized by the use of appropriate sensors and controllers. This paper describes a sensor developed for determining the amount of fluid (nutrient solution) available on the surface of a porous ceramic nutrient delivery substrate to the roots of conventional crop plants. The sensor is based on the change in thermal capacitance and thermal conductance near the surface as the moisture content changes. The sensor could be employed as a data acquisition and control sensor to support the automated monitoring of plants grown in a microgravity environment.
authors.affiliation: University of Florida, Gainesville, USA.
authors.forename: G J
authors.initials: GJ
authors.lastname: Clark
authors.forename: G E
authors.initials: GE
authors.lastname: Neville
authors.forename: T W
authors.initials: TW
authors.lastname: Dreschel
mesh_terms: D002516:Ceramics; D018504:Ecological Systems, Closed; D004867:Equipment Design; D005069:Evaluation Studies as Topic; D006358:Hot Temperature; D018527:Hydroponics / Q000295:instrumentation* / Q000379:methods; D008021:Life Support Systems / Q000295:instrumentation*; D018517:Plant Roots / Q000254:growth & development*; D012815:Signal Processing, Computer-Assisted; D013500:Surface Tension; D013696:Temperature; D013814:Thermal Conductivity; D014867:Water / Q000032:analysis*
chemical_list: D014867:Water