TDR100

Time-Domain Reflectometer
TDR100

TDR100

Retired

Time-Domain Reflectometer

No longer available to order

This product is retained for service, documentation, and compatibility information.

Replaced by

  • TDR200

    Time-Domain Reflectometer

Model:
TDR100
Item Number:
16594
Warranty:
1 year

Overview

The TDR100 Time-Domain Reflectometer is the core of the Campbell Scientific time-domain reflectometry system. This system is used to accurately determine soil volumetric water content, soil bulk electrical conductivity, rock mass deformation, or user-specific time-domain measurement. Up to 16 TDR100s can be controlled using a single Campbell Scientific data logger. PC-TDR software is used with our TDR100-based systems during system setup and troubleshooting. It can be downloaded from the Downloads section of the web page.

Technical Description

The TDR100 (1) generates a short rise time electromagnetic pulse that is applied to a coaxial system that includes a TDR probe for soil water measurements and (2) samples and digitizes the resulting reflection waveform for analysis or storage.

The elapsed travel time and pulse reflection amplitude contain information used by the on-board processor to quickly and accurately determine soil volumetric water content, soil bulk electrical conductivity, rock mass deformation or user-specific, time-domain measurement.

The data logger collects a 250-point waveform and analyzes it in approximately two seconds. Each waveform can have up to 2,048 data points for monitoring long cable lengths used in rock mass deformation or slope stability. Averaging up to 128 readings makes accurate measurements possible in noisy environments.

Benefits

  • Compact, low-cost reflectometer
  • Designed for use in remote applications
  • Determines volumetric water content and electrical conductivity in soil and other porous media
  • Compatible with CR800, CR850, CR1000, and CR3000 dataloggers

Specifications

Pulse Generator Output
250 mV into 50 Ω
Output Impedance
50 Ω ±1%
Time Response of Combined Pulse Generator & Sampling Circuit
≤ 300 ps
Pulse Length
14 µs
Timing Resolution
12.2 ps
Waveform Averaging
1 to 128
Electrostatic Discharge Protection
Internal clamping
Power Supply
Unregulated 12 V

(9.6 to 16 V)
300 mA maximum

Operating Temperature Range
-40° to +55°C
Pulse Generator Aberrations
±5%

(within first 10 ns)

±0.5%

(after 10 ns)

Dimensions
23.6 x 5.9 x 12.6 cm

(9.3 x 2.3 x 5.0 in.)

Weight
726 g

(1.6 lb)

Waveform Sampling

-NOTE-
20 to 2048 waveform values over chosen length



Distance is Vp=1. Time is one-way travel.

Range
-2 to 2100 m

(distance)

0 to 7 µs

(time)

Resolution
1.8 mm

(distance)

6.1 ps

(time)

Current Drain

During Measurement
270 mA
Sleep Mode
20 mA
Standby Mode
2 mA

Compatibility

Data Logger Considerations

To control the TDR100, the data logger uses TDR100 instruction in CRBasic or Instruction 119 in Edlog. All CR800-series, CR1000, and CR3000 operating systems (OS) are compatible with the TDR100. The CR10X operating system (OS) should be version 1 rev. 13 or higher and the CR23X OS should be version 1 rev. 10 or higher.

Enclosure Considerations

The TDR100 requires a desiccated, non-condensing environment; a Campbell Scientific enclosure is recommended. The TDR100's case has mounting flanges for attachment to the 1 in.-on-center hole grid of Campbell Scientific enclosures.

Related Resources

Services Available

Repair
Yes
Calibration
No
Free Support
Yes