The VP2 has hardware generation. So, unless the user changes something, the database will record whatever comes off the console. As for how Davis calculates rain rate, here's what they have to say in their "Derived Variables <https://support.davisinstruments.com/article/igpcv664kz-app-notes-derived-variables-in-davis-weather-products>" document.
RAINFALL RATE Parameters Used: Rain Total (actually, rain rate is a measured variable in the sense that it is measured by the ISS and transmitted to the display console, whereas all other calculated variables are determined by the console from data received from the ISS.) Formula: Under normal conditions, rain rate data is sent with a nominal interval of 10 to 12 seconds. Every time a rain tip or click occurs, a new rain rate value is computed (from the timer values) and the rate timers are reset to zero. Rain rate is calculated based on the time between successive tips of the rain collector. The rain rate value is the highest rate since the last transmitted rain rate data packet. (Under most conditions, however, a rain tip will not occur every 10 to 12 seconds.) If there have been no rain tips since the last rain rate data transmission, then the rain rate based on the time since that last tip is indicated. This results in slowly decaying rate values as a rain storm ends, instead of showing a rain rate which abruptly drops to zero. This results in a more realistic representation of the actual rain event. If this time exceeds roughly 15 minutes, than the rain rate value is reset to zero. This period of time was chosen because 15 minutes is defined by the U.S. National Weather Service as intervening time upon which one rain "event" is considered separate from another rain "event". This is also the shortest period of time that the Umbrella will be seen on the display console after the onset of rain. On Tue, Nov 4, 2025 at 12:21 PM vince <[email protected]> wrote: > Tom - how could weewx generate bizarre rainRate values in an archive > record when the amount of rain in an interval period looks reasonable ? > The station is a VP2. > > Here's one example related to that other long thread 'Correct Old and New > Rain Records'. > > sqlite3 query was: > > echo "SELECT interval,datetime(dateTime,'unixepoch','localtime'), > dateTime, rain, rainRate FROM archive where dateTime<1570838400 and > dateTime>=1570752000 ORDER BY rainRate DESC LIMIT 10;" | sqlite3 > ~/weewx-data/archive/weewx.sdb > > Just the interesting archive records.... > > 5|2019-10-11 21:45:00|1570830300|0.0|0.0 > 5|2019-10-11 21:50:00|1570830600|0.0|0.0 > 5|2019-10-11 21:55:00|1570830900|0.13|82.29 <== > 5|2019-10-11 22:00:00|1570831200|0.09|64.0 <== > 5|2019-10-11 22:05:00|1570831500|0.0|0.07 > 5|2019-10-11 22:10:00|1570831800|0.0|0.04 > 5|2019-10-11 22:15:00|1570832100|0.0|0.0 > 5|2019-10-11 22:20:00|1570832400|0.0|0.0 > > Total for that day was 0.23" so basically all was in that 10 minute period > > Other than a possibly broken/chattering tipper sensor, can you think of > anything ? > > -- > 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]. > To view this discussion visit > https://groups.google.com/d/msgid/weewx-user/e4e40f72-528a-4962-85f9-206b4d6f1212n%40googlegroups.com > <https://groups.google.com/d/msgid/weewx-user/e4e40f72-528a-4962-85f9-206b4d6f1212n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- 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]. To view this discussion visit https://groups.google.com/d/msgid/weewx-user/CAPq0zEDkQ7%3D1Wr%3D5ONRqchyAYBDTWzSGuG_5_NieMQVxxD9O%2Bw%40mail.gmail.com.
