All of our radars will measusre light or moderate to extremely heavy rain fall speed. Very light rain or mist may be traveling too slow for some radar models (all radars have a top and bottom speed measuring range).
PLEASE NOTE -- most radars are not hermetically sealed (weather resistant) and MUST be kept out of (protected from) the rain. Rain (water) will cause perminent damage. Some police radar antennas are weather resistant for outside use (mounted outside patrol).
Also the antenna must be pointed in the direction of rain (straight up usually). I found light rain with small drops travel about 10 to 12 mph (16 to 19 km/hr), heavy rain with big drops travel about 19 to 22 mph (30 to 35 km/hr). _________________ Best Regards,
Donald Sawicki
Radar Specialist
www.radarguns.com