It is on my to-do list to check my VP2 tipping bucket also, I will probably do this using a drip test. I have read a few forums that the VP2 can be very awkward to calibrate and may be best avoided unless absolutely necessary. I have also read (but can’t find the source at the moment) that the VP2 tipping bucket is biased for some reason, I haven’t found anything from Davis about this and what percentage it would need to be biased - 48-to-83 tips sounds high though.
I would be interested if anyone knows any more about this :?