On a rain gauge collector cone the effect is to avoid water collecting in large beads on the cone and instead running down the cone to be counted by rain gauge buckets. It might be worth an additional 0.01" of accuracy particularly when the rainfall is very light.
You might not find that very worthwhile or you might ... it all depends on how much time you have spent living in drought ...
Thanks for a simple explanation for my simple mind.
Not withstanding the possibility of a drought, if the climate warming process continues, I think the 0.01 accuracy is not worth the possible damage to the rain cone plastic. I've already applied a Rain-X layer and it appears its removal might be worse than another application. It does help on windshield, probably as much in not even having to use the wipers rather than running them on glass that still may have dry areas!
Once above ~40mph, it is only during moderate to heavy rain that the wipers are needed. Of course, wipers aren't much use if, like me, you close your eyes when being scared... even when driving!
I'll probably continue to rely on that force that keeps my feet on the ground now more than in the past,
Gravity, to get those droplets into the drip buckets.
In other, slightly related news, I watched a PBS show last week about the Giant Sequoias. A local lay-scientist had designed a 'rain-collector' that was completely covered by a 'roof'. He was not trying to measure "rain" falling from clouds as he was actually measuring the moisture
in 'special' clouds. These clouds were 'special' in the sense that they were actually at ground level, what we call "fog", a three-letter curse of many a pilot. His whole exercise was to measure how much water was available to trees in general and Sequoias in particular, even in a drought and when rain never reached their roots.
This collector appeared to be a series of dozens of vertically aligned, closely spaced (fish line) strings between an upper and lower arm. Three of these "fog combs" were arrayed around a central point where the lower "arms" met at a collector for all the drops that formed on the strings. The whole array was covered by what was basically an umbrella to keep out any falling precipitation.
The fog passing
through the array condensed on the strings, fell to the bottom and then into the central collector. Gravity provided the vertical force, pressure differences provide the horizontal force. No batteries included. No mention of Rain-X, Aquapel or any other chemicals or even wax!
They did, however, state that most of these giant trees were many decades older than any known Station Wagon!