Wxtech is correct!
You need to mount your CoCoRaHS gauge away from obstructions, and in "open" terrain, away from buildings or other interference.
If your electronic rain gauge is situated in a manner such as this then we presume you should be near, but "away" from it with your CoCoRaHS gauge.
Also, it's important that your CoCoRaHS gauge location be convenient for viewing, removal, and don't forget....periodic cleaning.
Mine gets full of pollen
There are great instructions on the CoCoRaHS website, as pointed out by Wxtech, that will assist you.
Good Luck!
A noteworthy commitment.
Henry