Cleaning
The CS120A/CS125 window will require cleaning from time to time. The frequency of required cleaning depends on exposure of the instrument to contaminants, such as salt and dust. This will vary depending on the site location. The CS120A/CS125 is capable of self-diagnosing a dirty window and will indicate in its output when the window is contaminated.
A lower level of contamination than is detected by the dirty window alarms, can affect the visibility measurements. The sensor can be configured to correct for low-level contamination, although the correction accuracy depends on the type of impurity.
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.
If the window requires cleaning, it is very important 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.
Use an air duster to blow any loose dust and dirt from the window. Using a lint-free lens cloth or lens tissue with a small amount of isopropyl alcohol solvent, clean the surface by dragging the cloth, being careful not to apply excessive pressure.
Excessive pressure may lead to some types of contaminant scratching the window surface. Scratches can lead to reduced sensitivity.
Spiders webs and certain seeds may get lodged in the optical path, leading to low readings and false precipitation reports. Cleaning the visibility contamination with a duster will return the sensor to normal operation. If spiders are a persistent problem, carefully applying insecticide can deter them. Avoid getting insecticide on the windows.