9.2 Cleaning
The CS140 window will require cleaning from time to time. The frequency of required cleaning
depends on the exposure of the instrument to contaminants such as salt and dust. This will vary
depending on the site location. The CS140 is capable of self-diagnosing a dirty window and will
indicate in its output when the window is contaminated.
Campbell Scientific suggests cleaning at six-month intervals for locations not prone to
contaminants and monthly intervals for those prone to contamination (coastal, roadside or
airport use). In some cases, more frequent cleaning may be required where there are high levels
of contaminants and high dependency on the instrument output.
CAUTION:
If the window requires cleaning, it is very important that only a proper lens cloth or lens tissue
is used. The use of inappropriate materials to clean the window can permanently damage or
reduce the effectiveness of the window leading to errors in measurement of precipitation and
visibility.
It is advisable to use an air duster to blow any loose dust and dirt from the window as a first step.
Using a lint-free lens cloth or lens tissue impregnated with a small amount of isopropyl alcohol
solvent, clean the surface by dragging the cloth across it being careful not to apply excessive
pressure.
CAUTION:
Excessive pressure may lead to some types of contaminant scratching the window surface.
Over time such scratches can lead to reduced sensitivity.
CS140 Background Luminance Sensor
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