This has me very confused - the lacrosse spec for the 2310 says rain is 0-9999 mm or 0-393.66 inches - implying it uses metric, and converts using 25.4 mm to the inch
I would hazard a guess that the bucket tip is a nice number in either metric or imperial - but do not see where the conversion of .518 comes from. .508 I could understand as it would match 1 tip = .02 inches = .508 mm On Sunday, 18 December 2016 09:57:16 UTC+2, Josh Smith wrote: > Your are correct that the driver uses 0.518 mm per bucket tip. However, > somewhere in the code it gets rounded up to 0.52 mm per bucket tip. This > would explain my 0.0204724409. Not sure where that happens exactly in the > driver. I will have to look at the driver more. Either way, the problem > with rounding up the sum remains. Thanks for looking into this Gary. > > Josh > > > > On Sunday, December 18, 2016 at 12:29:14 AM UTC-7, gjr80 wrote: >> >> I still think there is something screwy here. The lacrosse 23xx driver >> uses 0.518mm per bucket tip. weewx uses 25.4mm per inch so that is >> 0.0203937 inches per tip. So in your database you will see multiples of >> this value in the rain field (assuming you are using US customary units in >> your database). So if there were 2 tips in an archive period you should see >> 0.0407874 which is significantly different to the 0.04051811 number you >> have. That will certainly lead to discrepancies over a period of time. The >> irony of it is consider the month that had 0.32 inches. There was 16 bucket >> tips that month. if you take 16 bucket tips x 0.0203937 inches per tip you >> get 0.32629921 inches which is correctly rounded to 0.33 inches. >> 16 decimal places may be stored in the database but anything after 5 or 6 >> places will have no affect on anything weewx displays unless you are >> looking at a period that has 1000s of tips. >> >> Changing the formatting may give an acceptable result in this case but >> the issue will reappear at sometime while the above discrepancy remains. >> >> Gary >> >> -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
