Campbell LWS, Instruction Manual

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LWS Dielectric Leaf Wetness Sensor
7.2 Wiring
TABLE 7-1. Wire Color, Function, and Datalogger Connection
Color Function
CR200(X), CR6,
CR800/850, CR5000,
CR3000, CR1000, CR9000(X)
White Voltage Excitation Switched Voltage Excitation
Red Analog Out Single-Ended Channel
Bare Analog Ground
⏚
7.3 Programming
Short Cut is the best source for up-to-date datalogger programming code.
Programming code is needed
•
when creating a program for a new datalogger installation
• when adding sensors to an existing datalogger program
If your data acquisition requirements are simple, you can probably create and
maintain a datalogger program exclusively with Short Cut . If your data
acquisition needs are more complex, the files that
Short Cut
creates are a great
source for programming code to start a new program or add to an existing
custom program.
Short Cut cannot edit programs after they are imported and edited
in CRBasic Editor .
A Short Cut tutorial is available in Section 4 , Quickstart
(p. 2)
. If you wish to
import Short Cut code into CRBasic Editor to create or add to a customized
program, follow the procedure in Appendix Appendix A ,
Importing Short Cut
Code Into a Program Editor
(p. A-1)
. Programming basics for CRBasic
dataloggers are provided in the following sections. A complete program
example for a CRBasic datalogger can be found in Appendix B , Example
Programs
(p. B-1)
. Programming basics and programming examples for Edlog
dataloggers are provided at
www.campbellsci.com/old-manuals
.
7.3.1 Voltage Measurement
The LWS requires excitation voltage between 2.5 and 5 Vdc. It produces an
output voltage dependent on the dielectric constant of the medium surrounding
the probe. Output voltage ranges from 10 to 50% of the excitation voltage.
Except for the CR200(X), CRBasic dataloggers use the BRHalf() instruction to
measure the probe’s output. The BRHalf() instruction and parameters are as
follows:
BRHalf (Dest,Reps,Range,SeChan,ExChan,MeasPEx,ExmV,RevEx,Settling,Integ,
Mult,Offset)
NOTE
7