LWS Dielectric Leaf Wetness Sensor
6
7.2 Wiring
TABLE 7-1. Wire Color, Wire Function, and Data Logger Connection
Wire
Color
Wire Function
Data Logger Connection Terminal
Brown or
White
Voltage
excitation input
U
configured for voltage excitation
1
,
EX,
VX
(voltage excitation)
Orange or
Red
Analog voltage
output
U
configured for single-ended analog
input
1
,
SE
(single-ended, analog input)
Clear
Shield
⏚
(analog ground)
1
U
terminals are automatically configured by the measurement instruction.
7.3 Programming
Short Cut
is the best source for up-to-date data logger programming code.
If your data acquisition requirements are simple, you can probably create and
maintain a data logger 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
. 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
(p. A-1)
. Programming basics for CRBasic data
loggers are provided in the following sections. Complete program examples for
CRBasic data loggers can be found in Appendix
(p. B-1)
.
Programming basics and programming examples for Edlog data loggers 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 sensor. Output voltage ranges from 10 to 50% of the excitation voltage.
Except for the CR200(X), CRBasic data loggers use the
BRHalf()
instruction
to measure the sensor output. The
BRHalf()
instruction and parameters are as
follows:
BRHalf
(Dest,Reps,Range,SeChan,ExChan,MeasPEx,ExmV,RevEx,Settling,
fN1/Integ,Mult,Offset)
The CR200(X) uses the
ExDelSE()
CRBasic instruction to measure the sensor
output.
The ExDelSE() instruction
and parameters are as follows:
ExDelSE
( Dest, Reps, SEChan, ExChan, ExmV, Delay, Mult, Offset )
NOTE