Stevens Hydra Probe II Soil Moisture Sensors
The Stevens Hydra soil moisture sensor provides simultaneous measurement of soil moisture, salinity, and temperature using a unique patented design.
- Instantaneous sensor response with no calibration requirements
- Compact, rugged, zero-maintenance design for long-term deployments
- Easy integration with NexSens data logging & telemetry products
The Stevens Hydra Probe II soil moisture sensor is an in-situ soil probe that measures 21 different soil parameters simultaneously. The Stevens Hydra instantly calculates soil moisture, electrical conductivity, salinity, and temperature as well as supplying raw voltages and complex permittivity for research applications. A compact, rugged design with potted internal components makes the Hydra Probe easy to deploy and leave in the soil for years with no maintenance.
The Stevens Hydra probe design is unique compared to other soil moisture probes because the electrical response of soils can be specified by two parameters - the dielectric constant and the conductivity. The dielectric constant is most indicative of water content, while the conductivity is strongly dependent on soil salinity. Unlike other capacitance type sensors, the Hydra Probe measures both of these components simultaneously. The high frequency electrical measurements indicating the capacitive and conductive properties of soil are then directly related to the soil's moisture and salinity content, while a thermistor determines soil temperature.
The sensor includes built-in RS-485 and SDI-12 outputs for interfacing with NexSens iSIC and SDL data loggers. Sensor cable can be factory-connectorized with NexSens underwater connectors for integration to an SDL submersible data logger sensor port. Data collection options include direct-connect, landline phone, cellular, radio, Ethernet, WI-FI, and satellite telemetry. NexSens iChart Software is a Windows-based program for interfacing both locally (direct-connect) and remotely (through telemetry) to a NexSens data logger or network of data loggers.