Browse Publications Technical Papers 2004-01-2456

Accuracy of a Point Source Thermal Soil Moisture Sensor for Space Flight Nutrient Delivery Systems 2004-01-2456

The WONDER space flight experiment will compare the operation of both substrate-based and porous tube nutrient delivery systems (NDS) under microgravity conditions. Each NDS will be evaluated with three moisture availability regimes, and moisture sensing will be critical for the operation and evaluation of the systems. Orbital Technologies (Madison, WI) has developed a space flight-rated temperature and moisture acquisition system (TMAS) for measuring water content of plant growth medium. The sensors were evaluated in 0.25-1 mm and 1-2 mm baked ceramic aggregate (Profile and Turface, respectively). The sensors' pooled standard deviations ranged from approximately 2% to 5% relative water content (RWC), and root mean square error between sensor RWC and measured RWC was greater than 3% using linear calibration.


Subscribers can view annotate, and download all of SAE's content. Learn More »


Members save up to 43% off list price.
Login to see discount.
Special Offer: With TechSelect, you decide what SAE Technical Papers you need, when you need them, and how much you want to pay.