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DIGITAL SOLUTIONS

Metallic Time Domain Reflectometry (TDR)

Metallic Time Domain Reflectometry (TDR) System is a simple and economical way of detecting and interpreting rock and soil mass response to underground and surface mining using coaxial cables grouted in boreholes.

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Overview

RST’s Metallic Time Domain Reflectometry (TDR) System involves the installation of a coaxial cable in a borehole filled with grout that matches existing soil or rock conditions. A TDR readout or data logger unit is used to generate a voltage pulse along the cable and receive reflections. Reflections are generated by cable deformations, abrasions and severing. Crimps at known locations along the cable are used to provide depth datum.
As movement occurs, the reflections along the cable change as the cable deforms. By connecting the TDR200 Readout to a PC through Type A Micro B USB cable, or via FlexDAQ Data Logger, TDR reflections can be interpreted by analysis software, thereby inferring location, type and rate of earth movement.

Product features: 

  • Economic installation
  • Low data acquisition costs
  • Ability to monitor deformation along the entire length of the borehole
  • Can be used with RST’s FlexDAQ Data Loggers and GeoExplorer
     

Benefits

Data insights

Data insights

Ease of use

Ease of use

Improve safety

Improve safety

Features and benefits

Specifications

ItemSpecification
Tensile Strength113 kg
Maximum Tensile Force1100 N (247 lb)
Maximum (Recommended) Clamp Spacing0.6 / 1 m (2 / 3.25 ft)
Minimum Bending Radius, Single Bending70 mm (3 in.)
Minimum Bending Radius, Repeated Bending125 mm (5 in.)
Bending Moment6.5 Nm (4.79 lb-ft)
Installation Temperature– 40 to +60 °C (-40 to 140 °F)
Operation Temperature– 50 to +85 °C (-58 to 185 °F)
Storage Temperature– 70 to +85 °C (-94 to 185 °F)
Inner ConductorCopper-Clad Aluminium Wire, 4.8 mm (0.19 in.)
DielectricFoam Polyethylene, 11.9 mm (0.47 in.)
Outer ConductorCorrugated Copper, 13.8 mm (0.54 in.)
Jacket MaterialPolyethylene, PE 15.8 mm (0.62 mm)
Weight0.2 kg/m (0.14 lb/ft)
Characteristic Impedance50 ± 1 Ω
Relative Propagation Velocity88%
Capacitance76 pF/m (23.2 pF/ft)
Inductance0.19 μH/m (0.058 μH/ft)
Maximum Operating Frequency8.8 GHz
Jacket Spark Test RMS8000 V
Peak Power Rating38 kQ
RF Peak Voltage Rating1950 V
DC Resistance, Inner Conductor1.57 Ω/km (0.45 Ω/1000ft)
DC Resistance, Outer Conductor2.7 Ω/km (0.82 Ω/1000ft)

Industries

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Civil infrastructure

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Energy

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Surface metal

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Underground mining

Contact an expert

Whether you need support, want to request a quote or simply want to learn more, reach out to our Geosolutions team. We’re here to help.