Related Manuals for Campbell LWS
Summary of Contents for Campbell LWS
- Page 1 Dielectric Leaf Wetness Sensor Revision: 11/18 Copyright © 2008 – 2018 Campbell Scientific, Inc.
- Page 2 Limited Warranty “Products manufactured by CSI are warranted by CSI to be free from defects in materials and workmanship under normal use and service for twelve months from the date of shipment unless otherwise specified in the corresponding product manual. (Product manuals are available for review online at www.campbellsci.com.) Products not manufactured by CSI, but that are resold by CSI, are warranted only to the limits extended by the original manufacturer.
- Page 3 Campbell Scientific company serves your country. To obtain a Returned Materials Authorization (RMA) number, contact CAMPBELL SCIENTIFIC, INC., phone (435) 227-9000. Please write the issued RMA number clearly on the outside of the shipping container. Campbell Scientific’s shipping address is: CAMPBELL SCIENTIFIC, INC.
- Page 4 Periodically (at least yearly) check electrical ground connections. • WHILE EVERY ATTEMPT IS MADE TO EMBODY THE HIGHEST DEGREE OF SAFETY IN ALL CAMPBELL SCIENTIFIC PRODUCTS, THE CUSTOMER ASSUMES ALL RISK FROM ANY INJURY RESULTING FROM IMPROPER INSTALLATION, USE, OR MAINTENANCE OF TRIPODS, TOWERS, OR ATTACHMENTS TO TRIPODS AND TOWERS SUCH AS SENSORS, CROSSARMS, ENCLOSURES, ANTENNAS, ETC.
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Page 5: Table Of Contents
A. Importing Short Cut Code Into CRBasic Editor ... A-1 B. Example Programs ..........B-1 Example CR1000X Program ............B-1 Example CR6 Program ..............B-2 Figures 7-1. LWS Dielectric Leaf Wetness Sensor ..........5 7-2. Top view of a typical LWS installation ..........5 7-3. Typical LWS response .................7... - Page 6 Table of Contents Tables B-1. CR1000X Example Program Wiring ..........B-1 B-2. CR6 Example Program Wiring ............B-2 CRBasic Examples B-1. CR1000X Program for Measuring the LWS ........B-1 B-2. CR6 Program for Measuring the LWS ..........B-2...
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Page 7: Introduction
The LWS estimates leaf surface wetness by measuring the dielectric constant of the sensor upper surface. The LWS is able to detect the presence of miniscule amounts of water or ice. Individual sensor calibration is not normally necessary. - Page 8 Open Short Cut and click Create New Program. Double-click the data logger model. In the Available Sensors and Devices box, type LWS. You can also locate the sensor in Sensors | Miscellaneous Sensors folder. Double-click LWS Dielectric Leaf Wetness Sensor. Enter the Dry threshold (mV) <...
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Page 9: Overview
Short Cut program. Overview Measurement The LWS measures the dielectric constant of a zone approximately 1 cm from the upper surface of the sensor. The dielectric constant of water (≈80) and ice... -
Page 10: Leaf Mimicry
–1 . By mimicking the thermodynamic properties of a leaf, the LWS closely matches the wetness state of the canopy. The sensor closely matches the radiative properties of real leaves. Healthy leaves generally absorb solar radiation in much of the visible portion of the spectrum, but selectively reject much of the energy in the near-infrared. -
Page 11: Installation
, for a Short Cut tutorial. (p. 1) Field Installation The LWS includes two holes for mounting the sensor on a small diameter rod by using zip ties or 4-40 bolts (FIGURE and FIGURE 7-2). Typical deployment is in a plant canopy or on a weather station mast. -
Page 12: Wiring
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. -
Page 13: Minutes Dry, Minutes Wet Or Contaminated, And Minutes Wet
LWS Dielectric Leaf Wetness Sensor 7.3.2 Minutes Dry, Minutes Wet or Contaminated, and Minutes Wet The Voltage measurement can be further categorized into Minutes Dry, Minutes Wet or Contaminated, and Minutes Wet as follows: mV < 274 Then Minutes Dry = Scan Interval in seconds / 60 Else mV >= 284... -
Page 14: Maintenance
The LWS leaf wetness sensor withstands typical outdoor radiation and precipitation loads for more than two years. If using the LWS in areas with unusually high radiation loads, Campbell Scientific recommends applying Revivex UV Protectant (available from www.gearaid.com/products/revivex-... -
Page 15: Importing Short Cut Code Into Crbasic Editor
Appendix A. Importing Short Cut Code Into CRBasic Editor This tutorial shows: Importing a Short Cut program into a program editor for additional • refinement Importing a wiring diagram from Short Cut into the comments of a • custom program Short Cut creates files, which can be imported into CRBasic Editor. -
Page 16: Example Programs
TABLE B-1. CR1000X Example Program Wiring Color Function CR1000X Brown or White Excitation Orange or Red Analog Out ⏚ Clear Analog Ground CRBasic Example B-1. CR1000X Program for Measuring the LWS 'CR1000X 'Declare Variables and Units Public BattV Public PTemp_C Public LWmV Public LWMDry... -
Page 17: Example Cr6 Program
TABLE B-2. CR6 Example Program Wiring Color Function Brown or White Excitation Orange or Red Analog Out ⏚ Clear Analog Ground CRBasic Example B-2. CR6 Program for Measuring the LWS 'CR6 Series 'Declare Variables and Units Public BattV Public PTemp_C Public LWmV Public... - Page 18 'Default Data Logger Battery Voltage measurement 'BattV' Battery(BattV) 'Default Wiring Panel Temperature measurement '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 Contaminated 'LWMCon', 'and Minutes Wet 'LWMWet'. The value 0.08333333 is the scan rate divided by '60 s (5 s/60 s = 0.08333333).
- Page 19 Campbell Scientific Worldwide Offices Australia Germany Location: Garbutt, QLD Australia Location: Bremen, Germany Email: Email: info@campbellsci.com.au info@campbellsci.de Website: www.campbellsci.com.au Website: www.campbellsci.de Brazil South Africa Location: São Paulo, SP Brazil Location: Stellenbosch, South Africa Email: andread@campbellsci.com.br Email: sales@csafrica.co.za Website: Website: www.campbellsci.com.br www.campbellscientific.co.za...
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