To tell if the rain gauge is accurate or not, it is not correct to compare to a rain meter nearby around.
Because it is not necessary having a same rain intensity, even they are not far from each other. To judge if your rain meter is correct or not, you may do the following:
1. Use a narrowed neck bottle that can sit under the rain gauge water outlet holes.
Collect the water during a rain event and measure its weight. E.g.353 g.
2. 353 g equals 353 ml, divided by rain collector size of 250 cm2, you get 353/250 = 1.412 cm =14.1 mm.
3. Compare the rain readings from your console to your local rain event reading, or a reading from a calibrated manual gauge, to see if they are matching or not.
4. Since there may be some water left in the tip bucket, and also some on the rain collector itself, the observed rain is normally slightly less than the actual rainfall, but his is normally within 5%.
If the deviation is larger than this, then you can change rain calibration settings accordingly, or contact the customer service for replacement.