Campbell LWS, Руководство по эксплуатации продукта, Страница: 7 / 19

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LWS Dielectric Leaf Wetness Sensor
1. Introduction
Direct measurement of leaf wetness is problematic. Secure long-term
attachment of a sensor to a representative living leaf is difficult. Leaf position,
sun exposure, and health are in constant flux. To avoid these problems, leaf
wetness sensors have been developed to estimate by inference the wetness of
nearby leaves. 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.
This manual provides information only for CRBasic data loggers.
For retired Edlog data logger support, see an older manual at
www.campbellsci.com/old-manuals .
2. Precautions
• READ AND UNDERSTAND the Safety 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, contact Campbell
Scientific.
•
Although the LWS is rugged, it should be handled as a precision scientific
instrument.
• Over time, the accumulation of dust and bird droppings can cause the dry
output to rise. We recommend that the sensor be periodically cleaned
using a moist cloth, or when you detect elevated dry output.
• The LWS is intended only for applications wherein the data logger
provides short excitation, leaving the sensor quiescent most of the time.
Continuous excitation may cause the sensor to exceed government
specified limits on electromagnetic emissions.
3. Initial Inspection
• Upon receipt of the LWS, inspect the packaging and contents for damage.
File damage claims with the shipping company.
•
The model number and cable length are printed on a label at the
connection end of the cable. Check this information against the shipping
documents to ensure the correct product and cable length are received.
4. QuickStart
A video that describes data logger programming using Short Cut is available at:
www.campbellsci.com/videos/cr1000x-datalogger-getting-started-program-
part-3 . Short Cut is an easy way to program your data logger to measure the
LWS and assign data logger wiring terminals. Short Cut is available as a
NOTE