TDR100-Based System Time Domain Reflectometry Brochure

TDR100-Based System Time Domain Refl ectometry

Campbell Scientifi c’s Time Domain Refl ectometry (TDR) system is comprised of the TDR100 Time Domain Refl ectometer, a Campbell Scientifi c CR10X, CR800, CR850, CR1000, or CR3000 datalogger, SDMX50 coaxial multiplexers, TDR probes and PCTDR soft - ware. User-specifi c confi guration provides fl exibility for accurate and reliable soil water content and electrical conductivity measurement. Other applications include rock mass deformation, cable integrity monitoring, solution electrical conductivity, water level The TDR100 Refl ectometer is the core of Campbell Scientifi c’s Time Domain Refl ectometry (TDR) system. TDR systems are detection and laboratory time domain measurements. widely used to measure soil water content, bulk electrical conductivity, and rock mass deformation. TDR measurements are Features nondestructive and off er excellent accuracy and precision. • Uses compact, low-cost TDR100 Refl ectometer with performance features that match or exceed other available TDR refl ectometers (see specifi ca- Datalogger tions on last page) Th e TDR100-based system is supported by our • Makes non-destructive, long-term, in-situ soil CR10X, CR800, CR850, CR1000, and CR3000 data- measurements loggers. Th e datalogger is easily programmed for automatic control of the TDR100 and SDMX50 mul- • Provides measurement time of two seconds for tiplexers as well as telecommunication functions for water content, electrical conductivity or refl ection obtaining measurement results remotely. To control waveform collection (250 data points) the TDR100, the CR10X uses Instruction 119 and the • Measures up to 512 TDR probes CR800, CR850, CR1000, and CR3000 use the TDR100 • Uses PCTDR soft ware to facilitate system setup instruction. Th e CR10X operating system (OS) should • Supports operating temperature range of -40° to 55°C be version 1 rev. 13 or higher. All CR800, CR850, CR1000, and CR3000 operating systems (OS) are TDR100 Refl ectometer compatible with the TDR100. Th e TDR100 Time-Domain Refl ectometer is the core of the Campbell Scientifi c Time Domain Refl ectometry Power Supply system. Th e TDR100 (1) generates a very short rise Th e power supply requirements depend on the num- time electromagnetic pulse that is applied to a coaxial ber of sensors measured, how frequently the data’s system which includes a TDR probe for soil water mea- retrieved, data retrieval method used, and location of surements and (2) samples and digitizes the resulting the site. A typical system that measures 15 TDR sen- refl ection waveform for analysis or storage. Th e elapsed sors and uses phone modems to retrieve data every travel time and pulse refl ection amplitude contain two hours can use the datalogger’s sealed recharge- information used by the onboard processor to quickly able battery recharged by a 10 W solar panel. and accurately determine soil volumetric water content, soil bulk electrical conductivity, rock mass deformation Systems that measure more sensors, use a high or user-specifi c, time-domain measurement. current drain telecommunications method such as satellite transmitters, or retrieve data more frequently Up to 16 TDR100s can be controlled using a single may require a user-supplied, deep-cycle rechargeable Campbell Scientifi c datalogger. A 250-point waveform battery recharged with a 20 W solar panel. For infor- is collected and analyzed in approximately two seconds. mation about analyzing your system’s power require- Each waveform can have up to 2,048 data points for ments, see our Power Supply product brochure or monitoring long cable lengths used in rock mass defor- application note 5-F. Both can be downloaded from mation or slope stability. Averaging up to 128 makes our website at www.campbellsci.com. accurate measurements possible in noisy environments. Multiplexers SDMX50LP Campbell Scientifi c off ers three multiplexer models, • Consists of a multiplexer the SDMX50 series. Combining multiplexers allows circuit board attached to one measurement of up to 512 TDR probes. Th e SDMX50 end of a strain relief back series are 50 ohm, coaxial, 8:1 multiplexers with surge plate; dimensions of the back protection; 12 Vdc power is required. Th e multiplex- plate are 11.25” x 9.75” x 0.5” ers use Campbell Scientifi c’s SDM communications (28.6 x 24.8 x 1.3 cm) protocol and can be controlled via a datalogger or a • Mounts inside of a user- computer running PCTDR. Th e models diff er only in supplied enclosure their packaging. • Includes cable ties

SDMX50 SDMX50SP • Consists of a multiplexer circuit board mounted in • Consists of a multiplexer circuit board enclosed an environmental enclosure; inside dimensions of the in a metal housing and a separate strain relief enclosure are 10” x 12” x 5” (25.4 x 30.4 x 12.7 cm) bracket; dimensions of the multiplexer housing • Equipped with a back plate that provides a strain are 8.8” x 4.8” x 1.0” (22.3 x 12.2 x 2.5 cm), and relief point for coaxial cables dimensions of the strain relief bracket are 8.0” x 1.7” x 0.6” (20.3 x 4.3 x 1.5 cm) • Includes cable ties and desiccant • Mounts to a wall or to

L og an , U tah

SDMX50 the back plate of a user- 50 OHM MULTIPLEXER

C3 ENABLE C2 CLOC K C1 COMMON DATA +12V

GROUND

supplied enclosure or a MADE IN US A Campbell Scientifi c enclosure (e.g., ENCTDR100, ENC12/14, ENC16/18) • Includes cable ties and mounting hardware

Three Levels of Multiplexers

BATTERY - INTERNAL (12V 7 AMP HOUR) MADE IN USA BATTERY - EXTERNAL RECHARGEABLE BATTERY Logan, Utah CHARGE - CHARGING VOLTAGE PRESENT

OFF - ON - POWER TO 12V TERMINALS

WARNING: LIFT TO CHARGE PERMANENT DAMAGE TO REMOVE RECHARGEABLE CELLS MAY Level 1 Level 2 Level 3 FROM CHARGER OR SOLAR PANEL RESULT IF DISCHARGED CHARGE} 16-28VDC OR 18VAC RMS BELOW 10.5 VOLTS + TO EITHER TERMINAL, – TO OTHER +12V +12V POWER TO DATALOGGERS OR 12V PERIPHERALS PS100 12V POWER SUPPLY } WITH CHARGING REGULATOR Includes multiplexer Supports up to eight Supports up to

POWER IN SE 12 34 56 78 G 12V DIFF 1234 EX1 P2 P1 and TDR100 reflec- multiplexers increas- H L H L HL HL CAUTION 64 multiplexers DC ONLY

G 12V GROUND LUG CR1000 SE 9 10 11 12 13 14 15 16 WIRING PANEL DIFF 5678 tometer controlled ing system capacity increasing sys- EX3 H L H L HL HL EX2

RS-232 (Not Isolated)

POWER OUT COM1 COM2 COM3 COM4 Tx Rx Tx Rx Tx Rx Tx Rx CS I/O by the datalogger to 64 probes tem capacity to PERIPHERAL PORT SW-12 G G G G C1 C2 C3 C4 G C5 G 5V 12V 12V C6 C7 C8

SN: SDM MADE IN USA 512 probes

SELECTION SDM ADDRESS 000 101 202 Logan, Utah 303 410 511 612 TDR100 713 820

TIME DOMAIN REFLECTOMETER +12V GROUND C1 DATA C2 CLOCK C3 ENABLE RS232 921SDM A22 B23 C30 D31 E320 S/N MADE IN USA

C3 C2 C1 ENABLE CLOCK DATA +12V GROUND

Logan, Utah SDMX50 50 OHM MULTIPLEXER

MADE IN USA

SDM cable(s) for multiplexer control SDM cable(s) Coaxial cable(s) to probes only

Coaxial cable(s) to probes or multiplexers

The system can use three multiplexer levels allowing up to 512 probes to be measured. The first level includes the TDR100 and one multiplexer. Up to eight coaxial cables connect to each multiplexer. The coaxial cables can be connected to TDR probes or the next level’s multiplexers.

2 ENCTDR100 Environmental Enclosure Th e refl ectometer, datalogger, multiplexer and power Th e ENCTDR100 includes interconnecting SDM and supply should be housed in an environmental enclo- coaxial cabling, grounding wires, desiccant, humidity sure to protect the equipment from weather, condens- indicator, and hardware for mounting the enclosure on ing humidity, and dust. Campbell Scientifi c off ers the a pole, tripod mast, or tower leg. ENCTDR100 for this purpose. Th e ENCTDR100 is a white fi berglass-reinforced Telecommunications polyester enclosure that has internal dimensions Data retrieved via telecommunications is available of 16” x 18” x 8”. It can house the datalogger, data- using the CR10X, CR800, CR850, CR1000, or CR3000 logger’s power supply, TDR100, and SDMX50SP dataloggers. Th e dataloggers are compatible with (the SDMX50 includes its own enclosure and the direct connection with the computer, radio telemetry, SDMX50LP is intended to be mounted in a separate phone lines (land-line and cellular), multidrop mo- user-supplied enclosure). dems, and short-haul modems.

Sensors coaxial cable 7.0 cm Soil TDR Probes Th e probes act as a wave guide. Impedance along the 10.9 cm rods varies with the dielectric permittivity of the sur- ↕ ↓ rounding soil. Because the dielectric permittivity of soil stainless steel rods ↔ 0.48 cm diameter primarily depends on the amount of water present, soil ↑ volumetric water content can be inferred from the re- 2.0 cm

fl ected measurements. Soil bulk electrical conductivity

↕

is determined from the attenuation of the applied pulse. ↕ 2.2 cm evenly spaced (center-to-center) Campbell Scientifi c off ers six soil probes that have diff erent rods and connector cables allowing them to be used in diff erent soil types and with diff erent cable lengths. Th e probes consist of three pointed rods and • CS640 probe—recommended for very high con- a rugged head. Insertion guides are available that aid ductivity soils (soil bulk conductivity ≤5 dS/m) or probe installation. laboratory column applications and cable lengths ≤15 m. Probe has an RG58 cable, and rods with a • CS605 probe—recommended for typical soils (soil 7.5-cm length and 0.159-cm diameter. bulk conductivity ≤1.4 dS/m) and cable lengths • CS645 probe—recommended for very high con- ≤15 m. Probe has an RG58 cable, and rods with a ductivity soils (soil bulk conductivity ≤5 dS/m) 30-cm length and 0.48-cm diameter. or laboratory column applications and cable • CS610 probe—recommended for typical soils (soil lengths ≤25 m (as measured from the tips of bulk conductivity ≤1.4 dS/m) and cable lengths the probe’s rods to the TDR100). Probe has an ≤25 m (as measured from the tips of the probe’s LMR200DB cable, and rods with a 7.5-cm length rods to the TDR100). Probe has an RG8 cable,and and 0.159-cm diameter. rods with a 30-cm length and 0.48-cm diameter. Sensor Cables for Rock Mass Deformation • CS630 probe—recommended for high conductivity Rock mass deformation applications use a coaxial cable soils (soil bulk conductivity ≤3.5 dS/m) and cable grouted into a borehole to serve as the system’s sensor. lengths ≤15 m. Probe has an RG58 cable, and rods Crimps at measured intervals along the cable partially with a 15-cm length and 0.318-cm diameter. refl ect the transmitted signal. Crimps appear as small • CS635 probe—recommended for high conductiv- negative polarity events along the trace of the waveform. ity soils (soil bulk conductivity ≤3.5 dS/m) and Events that off set the waveform indicate deformational cable lengths ≤25 m (as measured from the tips zones. Th e polarity of the off set indicates whether a of the probe’s rods to the TDR100). Probe has an zone is experiencing tensile or shear deformation. LMR200DB cable, and rods with a 15-cm length Coaxial cable suitable for grouting is obtained by the user. and 0.318-cm diameter.

3 Software Specifi cations We recommend that you confi rm system confi guration and critical PCTDR specifi cations with Campbell Scientifi c before purchase. PCTDR soft ware is used during system setup and troubleshooting to display volumetric water content TDR100 Performance and electrical conductivity, switch multiplexer chan- Pulse Generator Output: 250 mV into 50 ohms nels, collect waveform and derivative data fi les, and Output Impedance: 50 ohms ±1% determine probe constant values needed for electrical conductivity measurements. A Windows® 98, NT, Time Response of Combined Pulse Generator and 2000 or XP computer operating system is required. Sampling Circuit: ≤300 ps Pulse Generator Aberrations Within fi rst 10 ns: ±5% After 10 ns: ±0.5% Pulse Length: 14 μs Timing Resolution: 12.2 ps Waveform Sampling: 20 to 2048 waveform values over chosen length

distance (Vp = 1) time (1 way travel) range -2 to 2100 m 0 to 7 μs resolution 1.8 mm 6.1 ps

Waveform Averaging: 1 to 128 PCTDR displays waveforms for system setup and trouble- Electrostatic Discharge shooting. A CD containing PCTDR is shipped with each Protection: Internal clamping TDR100 Reflectometer. This software is also available, at no charge, from our website. Current Drain During Measurement: 270 mA Sleep Mode: 20 mA LoggerNet Standby Mode: 2 mA LoggerNet Datalogger Support Soft ware provides telecommunications, datalogger programming, data Power Supply: Unregulated 12 V (9.6 V to 16 V), 300 mA maximum transfer, and data processing functions. Th e TDR100- based system requires LoggerNet 2.0 or higher. Our Operating Temperature: -40° to +55°C CR1000 requires LoggerNet 3.0 or higher; our CR3000 Dimensions: 21 x 11 x 5.5 cm requires LoggerNet 3.2 or higher, and our CR800- (8.3” x 4.3” x 2.2”) series requires LoggerNet 3.3 or higher. Weight: 700 g (1.5 lb)

TDRSDK (Optional) Multiplexer Power Requirements TDRSDK Software Developers Kit allows software • Multiplexer requires 12 Vdc. developers to customize and simplify the user- • Quiescent current demand for the multiplexer is interface for the TDR100. The kit consists of a DLL less than 1 mA. (dynamically linked library) file that gives devel- • Current demand during switching is approximately opers access to the entire TDR100 command set. 90 mA. The TDR100COM.DLL runs in a Windows 98, NT, • All multiplexers of the same level switch simultaneously. 2000, XP computer operating system. The custom Switching takes less than 1 s. interfaces can be created using C++, Pascal, or VisualBasic computer languages.