Campbell Scientific CS650 and CS655 Water Content Reflectometers - Manual (Page 6)

Table of Contents
7.2 The Topp Equation ............................................................................ 25
7.3 Electrical Conductivity ...................................................................... 25
7.3.1 Soil Electrical Conductivity ....................................................... 25
7.3.2 Temperature Correction of Soil Electrical Conductivity ............ 26
7.4 Error Sources in Water Content Reflectometer Measurement .......... 27
7.4.1 Probe-to-Probe Variability Error ................................................ 27
7.4.2 Insertion Error ............................................................................ 27
7.5 Temperature Dependence and Correction ......................................... 27
7.5.1 Accurate Soil Temperature Measurement .................................. 28
8. Water Content Reflectometer User-Calibration ...... 28
8.1 Need for Soil Specific Calibration Equation ..................................... 28
8.2 The User-Derived Calibration Equation ............................................ 28
8.3 Collecting Laboratory Data for Calibration ....................................... 29
8.4 Collecting Field Data for Calibration ................................................ 31
8.5 Calculations ....................................................................................... 33
9. Maintenance .............................................................. 33
10. Troubleshooting ........................................................ 34
11. References ................................................................. 35
Appendices
A.
Discussion of Soil Water Content ......................... A-1
B. SDI-12 Sensor Support ........................................... B-1
B.1 SDI-12 Command Basics ................................................................ B-1
B.2 Changing the SDI-12 Address Using Terminal Emulator and a
Datalogger .................................................................................... B-3
B.2.1 SDI-12 Transparent Mode ........................................................ B-3
B.2.2 CR200(X) Series Datalogger Example .................................... B-4
B.2.3 CR1000 Datalogger Example ................................................... B-5
B.2.4 CR10X Datalogger Example .................................................... B-6
B.2.5 CR10X-PB Table-Based Datalogger Example ......................... B-7
Figures
4-1. CS650 Water Content Reflectometer .................................................. 2
5-1. CS650 and CS655 average current drain ............................................. 5
6-1. CS650G Insertion Guide Tool ............................................................. 8
6-2. A200 Sensor-to-PC Interface ............................................................. 11
B-1. SDI-12 transparent mode on CR200(X)-series datalogger using
control port C1/SDI12 and changing SDI-12 address from 0
to 1 ............................................................................................... B-4
B-2. SDI-12 transparent mode on CR1000 datalogger using control
port 1 and changing SD1-12 address from 3 to 1 ......................... B-5
B-3. SDI-12 transparent mode on CR10X datalogger using control
port 1 and changing SDI-12 address from 0 to 1 ......................... B-7
B-4. SDI-12 transparent mode on CR10X-PB table-based datalogger
using control port 1 and changing SDI-12 address from 0 to 1 ... B-8
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