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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

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 

Содержание LWS

Страница 1: ...INSTRUCTION MANUAL LWS Dielectric Leaf Wetness Sensor Revision 2 15 C o p y r i g h t 2 0 0 8 2 0 1 5 C a m p b e l l S c i e n t i f i c I n c...

Страница 2: ......

Страница 3: ...ucts to CSI CSI will return such Products by surface carrier prepaid within the continental United States of America To all other locations CSI will return such Products best way CIP port of entry per...

Страница 4: ...g container Campbell Scientific s shipping address is CAMPBELL SCIENTIFIC INC RMA _____ 815 West 1800 North Logan Utah 84321 1784 For all returns the customer must fill out a Statement of Product Clea...

Страница 5: ...ore beginning work Wear a hardhat and eye protection and take other appropriate safety precautions while working on or around tripods and towers Do not climb tripods or towers at any time and prohibit...

Страница 6: ......

Страница 7: ...5 2 Leaf Mimicry 4 6 Specifications 5 7 Installation 6 7 1 Field Installation 6 7 2 Wiring 7 7 3 Programming 7 7 3 1 Voltage Measurement 7 7 3 2 Interpreting Data 8 8 Maintenance 9 9 Acknowledgement...

Страница 8: ...Table of Contents Tables B 1 CR1000 Example Wiring B 1 B 2 CR6 Example Wiring B 2 ii...

Страница 9: ...RSTAND the Precautions section at the front of this manual Care should be taken when opening the shipping package to not damage or cut the cable jacket If damage to the cable is suspected consult with...

Страница 10: ...ort Cut to program the LWS 1 Install Short Cut by clicking on the install file icon Get the install file from either www campbellsci com the ResourceDVD or find it in installations of LoggerNet PC200W...

Страница 11: ...ilable Sensors and Devices list select the Sensors Miscellaneous Sensors folder Select LWS Dielectric Leaf Wetness Sensor Click to move the selection to the Selected device window Enter the Dry thresh...

Страница 12: ...ogger as shown in the wiring diagram in step 6 check the output of the sensor in the datalogger support software data display to make sure it is making reasonable measurements 5 Overview 5 1 Measureme...

Страница 13: ...a healthy leaf During normal use prolonged exposure to sunlight can cause some yellowing of the coating which does not affect the probe s function The surface coating is hydrophobic similar to a leaf...

Страница 14: ...tion 4 Quickstart p 2 for a Short Cut tutorial 7 1 Field Installation The LWS is designed to be mounted on a small diameter rod Deployment in a plant canopy or on a weather station mast is typical Two...

Страница 15: ...nd 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 p...

Страница 16: ...y 475 mV when frosted and 475 mV when wet Therefore a Boolean wetness threshold of 500 mV should serve well for interpreting these data FIGURE 7 3 Typical LWS response Duration of leaf wetness can be...

Страница 17: ...cipitation loads for greater than two years If you are using the LWS in areas with non typical unusually high radiation loads we recommend additional applications of McNett UVTech available from www m...

Страница 18: ...LWS Dielectric Leaf Wetness Sensor 10...

Страница 19: ...and exit Short Cut Make note of the file name used when saving the Short Cut program 2 Open CRBasic Editor 3 Click File Open Assuming the default paths were used when Short Cut was installed navigate...

Страница 20: ...Appendix A Importing Short Cut Code Into a Program Editor mark begins each line This character instructs the datalogger compiler to ignore the line when compiling the datalogger code A 2...

Страница 21: ...nits LWMWet Minutes Define Data Tables DataTable Table1 True 1 DataInterval 0 60 Min 10 Sample 1 BattV FP2 Sample 1 PTemp_C FP2 Sample 1 LWmV FP2 Totalize 1 LWMDry FP2 False Totalize 1 LWMCon FP2 Fals...

Страница 22: ...The wiring for the example is shown in TABLE B 2 TABLE B 2 CR6 Example Wiring Color Function CR6 White Excitation U1 Red Analog Out U2 Bare Analog Ground CR6 Series Declare Variables and Units Public...

Страница 23: ...surement PTemp_C PanelTemp PTemp_C 60 LWS Dielectric Leaf Wetness Sensor measurement LWmV BrHalf LWmV 1 mV5000 U2 U1 1 2500 False 10000 60 2500 0 Determine Minutes Dry LWMDry Minutes Wet or Contaminat...

Страница 24: ...Appendix B Example Programs B 4...

Страница 25: ......

Страница 26: ...m br Campbell Scientific Canada Corp CSC 14532 131 Avenue NW Edmonton AB T5L 4X4 CANADA www campbellsci ca dataloggers campbellsci ca Campbell Scientific Centro Caribe S A CSCC 300 N Cementerio Edific...

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