Campbell Scientific 229 Water Matric Potential Sensor and CE4/CE8 - Manual (Page 3)

229 Sensor Table of Contents
PDF viewers note: These page numbers refer to the printed version of this document. Use
the Adobe Acrobat® bookmarks tab for links to specific sections.
1. General Description
.....................................................1
1.1 Compatibility ............................................................................................2
1.2 Measurement Principle .............................................................................2
2. Specifications
..............................................................4
3. Installation
....................................................................4
3.1 Orientation ................................................................................................4
3.2 Contact......................................................................................................4
3.3 Equilibration and Saturation of the Sensor Before Installation ................5
4. Wiring
............................................................................5
5. Example Programs
......................................................6
5.1 Choosing a Reference for the Thermocouple Readings ...........................6
5.2 Adjusting for Thermal Properties of Sensor During Early Heating Times7
5.3 Datalogger Program Structure and Multiplexers ......................................7
5.4 Temperature Correction............................................................................8
5.5 Example #1 — CR1000 with CE4 and Four 229s....................................9
5.6 Example #2 — CR1000 with AM16/32-series Multiplexer,
CE4 and Sixteen 229 Sensors with Temperature Correction .............11
5.7 Example #3 — CR10X with 229 Sensor................................................13
5.8 Example #4 — CR10X with AM16/32-series, CE4, and
Sixteen 229 Sensors ...........................................................................16
6. Calibration
..................................................................19
6.1 General....................................................................................................19
6.2 Normalized Temperature Change and Correction for Soil Temperature......20
6.2.1 Normalized Temperature Change .................................................20
6.2.2 Correction for Soil Temperature ...................................................21
6.3 Using Pressurized Extraction Methods...................................................24
6.4 General Description of Calibration/Measurement Process using
Pressure Plate Extractor .....................................................................24
6.4.1 Wiring for Calibration using Pressure Plate Extractor..................25
7. Maintenance
...............................................................26
8. Troubleshooting
........................................................27
i