HydraProbe is a rugged soil sensor with patented technology that provides continual, consistent accuracy measuring the three most significant soil parameters simultaneously - moisture, salinity and temperature. As the most scientifically researched soil sensor available, it has been depended on by the USDA, NOAA, NASA, leading irrigation companies, and many universities for over 20 years. It`s been engineered to be exceptionally rugged and will provide data that you can trust year after year.