Digital TDR Soil Moisture Sensor

The TDR-315L is a true waveform digitizing Time Domain Reflectometer that derives soil permittivity and water content from the propagation time of an electromagnetic impulse conveyed along its waveguide. Like many of its expensive predecessors (conventional TDR mainframes) it contains an ultra-fast rise time step function generator, a waveform digitizer (200 GSPS) and a picosecond-resolution time base (5ps). Unlike these predecessors it eliminates the bandwidth-constraining coax cable, the bulky console, and 90-97% of the cost. Because it is a true time domain device its readings are not derived from current and voltage magnitudes and relationships and hence are not impacted by soil electrical conductivity and compaction. Its high immunity to EC allows credible application in non-saturated soils wetted with sea water. It uses the standard SDI-12 interface and is compatible with all data recorders that are version 1.3 compliant.

Functions:

• Volumetric Water Content (0 to 100% with 0.1% resolution)

• Permittivity (1 to 80 with 0.1 unit resolution)

• Soil Electrical Conductivity a.k.a. Bulk EC (0 to 5000 μS/cm -resolution depends on reading range)

• Soil Temperature (-40 to +60 degrees C with 0.1 degree resolution)

• Pore Water Electrical Conductivity (0 to 55000 μS/cm)