Campbell Scientific TDR100 Time Domain Reflectometry Systems - Manual (Page 4)

TDR100 Table of Contents
5.8 Soil Probes ............................................................................................. 17
5.8.1 Determining Probe Constant, Kp, using PCTDR......................... 18
6. Datalogger Instructions for TDR Measurements ....18
6.1 CR800, CR850, CR1000, or CR3000 Datalogger Instruction “TDR100”18
6.2 CR10X and CR23X Datalogger Instruction 119 ................................... 20
6.3 Discussion of TDR Instruction Parameters (Instruction 119)................ 21
6.3.1 Parameter 1: SDM Address.......................................................... 21
6.3.2 Parameter 2: Output Option ......................................................... 21
6.3.2.1 Enter 0: Measure La/L........................................................ 21
6.3.2.2 Enter 1: Collect Waveform................................................. 22
6.3.2.3 Enter 2: Collect Waveform and First Derivative ................ 22
6.3.2.4 Enter 3: Measure Bulk Electrical Conductivity.................. 22
6.3.3 Parameter 3: Multiplexer and Probe Selection............................. 22
6.3.4 Parameter 4: Waveform Averaging.............................................. 23
6.3.5 Parameter 5: Relative Propagation Velocity ................................ 23
6.3.6 Parameter 6: Points....................................................................... 23
6.3.7 Parameter 7: Cable Length (meters)............................................. 23
6.3.8 Parameter 8: Window Length (meters) ........................................ 24
6.3.9 Parameter 9: Probe Length (meters)............................................. 24
6.3.10 Parameter 10: Probe Offset (meters) .......................................... 24
6.3.11 Parameter 11: Input Location..................................................... 24
6.3.11.1 Reflection Waveform Values to Input Storage................. 24
6.3.12 Parameter 12: Multiplier ............................................................ 25
6.3.13 Parameter 13: Offset................................................................... 25
6.3.13.1 Probe Constant for Electrical Conductivity Measurement 25
7. TDR Principles
...........................................................26
8. Cable Length and Soil Electrical Conductivity Effect
on Water Content Determination
...........................28
8.1 Cable Length Effect on Water Content Measurement ........................... 28
8.2 Soil Electrical Conductivity Effect on Water Content Measurement .... 29
9. Algorithm Description and Parameter Adjustment
...30
9.1 Introduction............................................................................................ 30
9.2 Algorithm for Calculation of TDR Probe Rod Apparent Length........... 30
9.2.1 Algorithm Description.................................................................. 30
9.2.1.1 Waveform Evaluation......................................................... 31
9.2.2 Algorithm Parameter Adjustment for Special Conditions............ 32
9.2.2.1 Terminal Emulator Commands for Apparent Length
Algorithm ........................................................................ 32
9.3 Algorithm for Calculation of Bulk Electrical Conductivity................... 33
9.3.1 Algorithm Description.................................................................. 33
9.3.2 Algorithm Parameter Adjustment for Special Conditions............ 33
10. Programming Examples
..........................................35
10.1 CR1000 Program Example .................................................................. 35
10.2 CR10X/CR23X Program Examples..................................................... 38
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