The HydraGO and HydraGO FLEX represent the most advanced portable soil sensor system. Simply insert the probe into the soil, and tap on the “Sample” button in the HydraGO app. The HydraGO and HydraGO FLEX communicate wirelessly with your smartphone or tablet using Bluetooth. Both systems features a rugged, Delran housing that contains a rechargeable battery. The internal battery will last for long field sessions with repeated and frequent data samplings.

The HydraGO has a probe on the end of a shaft for easy surface measurements. It includes 4 segments so that the size can be adjusted from 25 to 84 cm (10 to 33 inches).

The HydraGO FLEX has a detachable cabled probe that can be buried and left in the field. The cabled probe allows the user to collect data down a narrow-augured bore hole. The HydraGO FLEX comes with a fanny pack and brush for easy on-the-go measurements.

The HydraGO App works with both HydraGO and HydraGO FLEX and is available for both Android and iOS. The customizable display can show the measurement parameters including; soil moisture content, temperature, conductivity, pore water EC, GPS, and dielectric permittivities on-screen for immediate viewing. The GPS location, date and time of each measurement is recorded along with the soil measurement data. All data can be saved and emailed as a .CSV file for analysis in Excel. Field notes and customizable locations can also be added and exported to the data set.

Both HydraGO and HydraGO FLEX utilize the HydraProbe Soil Sensor technology for the soil measurements. The HydraProbe is an impedance-based sensor that fully characterizes the radio frequency energy distribution of a standing wave in the soil measuring both the real and “imaginary” dielectric permittivities. This provides excellent accuracy and precision of the soil measurements across a wide range of soil types.

Technical Specifications

HydraGO ModelsHydraGOHydrdaGO Flex
ConfigurationSensor on a ShaftSensor on a detachable Cable
GPSPhone GPSInternal GPS, +/- 2 meters
Wireless ProtocolBluetoothBluetooth
App (Android or iOS)HydraGOHydraGO
Battery TypeRechargeable Lithium Ion battery, 3.7 V / 10500 mAhRechargeable Lithium Ion battery, 3.7 V / 10500 mAh
Weight3.28lbs (1.49kg) with 4 segments1.88lbs ( 0.85 kg )
DimensionsBody: 9.75” L x 3.5” W x 2.5” D (24.8cm L x 8.9cm W x 6.4cm D)Segment: 5.5” long (14cm)Body: 4.5” L x 2.75” W x 2.25” D (11.4cm L x7.0 cm W x 5.7 cm D)
Part Numbers93633-007: Complete unit with 4 segments and 1 knob.

93633-175: Knob 93633-176: Segment
93633-500: Complete unit with one HydraProbe Flex Sensor.

93633-501: Standalone HydraProbe Flex Sensor.
HydraProbe Flex Soil Sensor
Soil probeStevens HydraProbe (ratiometric dielectric coaxial impedance)
Parameters measuredSoil moisture, temperature, bulk electrical conductivity, Porewater EC, dielectric permittivities
Pore Water EC methodHilhorst Equation
MoistureRange: From completely dry to fully saturated (from 0% to 100% of saturation) Accuracy: ± 0.01 WFV for most soils, ± ≤0.03 max for fine textured soils*
Bulk electrical conductivityRange: 0 to 1 S/m (or 0 to 10 dS/m)± 2.0% or 0.02 S/m whichever is typically greater*
Real dielectric permittivity (isolated)Range: 1 to 80 where 1 = air, 80 = distilled water Accuracy: ± 0.5% or ± 0.2 dielectric units
Operating temperature14°F to 149°F (-10°C to +65°C), Accuracy: ± 0.3° C
Soil tine assemblyHardened Marine grade stainless steel
Tine dimensions6 cm long. Measurement volume is 50 to 75 cubic cm
CalibrationSeyfried Equation default for most soils with peat/organic and custom calibration options


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