restricted from any light source with ultra-violet rays,
such as halogen light, sun light, mercury light, electric
insecticide light, lighter, spark of electric appliance,
welding spark, sunshine, etc. Any other light sources with ultra-violet rays also cannot
directly shine on the UV pipe of the detector.
Detecting area: About 65
degrees around the perpendicular side, and 65 degrees
above and below the water level.
Effective sensing distance: Within 30 meters.