The TDR200 Time-Domain Reflectometer is the core of the Campbell Scientific time-domain reflectometry (TDR) system. TDR systems accurately determine soil volumetric water content, soil bulk electrical conductivity, rock mass deformation, or a user-specific time-domain measurement. One Campbell Scientific data logger can control multiple TDR200 reflectometers.Read More
|Pulse Generator Output||250 mV into 50 Ω|
|Output Impedance||50 Ω ±1%|
|Time Response of Combined Pulse Generator & Sampling Circuit||≤ 85 ps|
|Pulse Generator Aberrations||
|Pulse Length||25.5 μs|
|Waveform Averaging||1 to 128|
|Operating Temperature Range||-40° to +85°C|
Unregulated 12 Vdc
(9.6 to 16 Vdc)
150 mA maximum, USB powered (5 Vdc)
|Dimensions||21.6 x 5.1 x 10.7 cm (8.5 x 2.0 x 4.2 in.)|
|Weight||0.79 kg (1.75 lb)|
20 to 10112 waveform values over chosen length
Distance is Vp=1. Time is one-way travel.
Electrostatic Discharge Protection
|Air||±8 kV @ 2 Ω|
|Contact||±4 kV @ 2 Ω|
|Surge||±2 kV @ 2 Ω|
|During Measurement||120 mA|
|Sleep Mode||1 mA|
Number of FAQs related to TDR200: 2
In applications where TDR probes are used to measure soil water content, the maximum distance from the TDR probe back to the TDR100/TDR200 (even through one or more multiplexers) cannot exceed 15 m (50 ft) when using RG58 coaxial cable; the CS605-L, CS630-L, and CS640-L TDR probes have an RG58 cable. When using low-loss coaxial cable, the distance cannot exceed ≈25 m (80 ft); the CS610-L, CS635-L, and CS645-L TDR probes have a low-loss coaxial cable.
In slope stability and rock mass deformation applications, the maximum coaxial cable length should not exceed ≈1 mile (5,280 ft). The maximum combined length of all SDM cables in the system should not exceed ≈76 m (250 ft).