thank's Florentin, I've just opened a ticket on Davis support, I will give you the result next week I hope.
Le dim. 22 nov. 2020 à 14:24, flor...@pre-vost.fr <floren...@pre-vost.fr> a écrit : > Hi, > > I'm the author of WLLDriver on Github. > Yes, I think that *altimeter *is the good value. But I suggest to confirm > that by directly ask Davis. > > Regards, > > Le samedi 21 novembre 2020 à 22:31:04 UTC+1, kk44...@gmail.com a écrit : > >> I found that additional information at >> https://www.manula.com/manuals/pws/davis-kb/1/en/topic/barometric-pressure-issues >> . >> >> There they say, that Davis uses different calculations in different >> devices: >> >> - VP2 and envoy consoles: sea-level pressure ("barometer", QFF) >> - WeatherLinkLive: altimeter pressure ("altimeter", QNH) >> - Vue consoles: user can choose between the two >> >> So it seems, the author of the "weatherlinkliveudp" driver read the >> documentation most carefully. >> >> And to confuse the user or something, in the LOOP data record, Davis >> calls the value, what we learnt is altimeter, "bar_sea_level". >> >> The archive record contains all the three values barometer, altimeter, >> and pressure (I checked). Since the "weatherlinkliveudp" driver does not >> provide a value for barometer, may be, WeeWX calculates it by itself. >> >> didier....@gmail.com schrieb am Samstag, 21. November 2020 um 20:54:45 >> UTC+1: >> >>> Thank's a lot >>> I'm learning a lot of things with you >>> >>> Le sam. 21 nov. 2020 à 18:59, vince <vince...@gmail.com> a écrit : >>> >>>> On Saturday, November 21, 2020 at 9:31:11 AM UTC-8 kk44...@gmail.com >>>> wrote: >>>> >>>>> didier....@gmail.com schrieb am Samstag, 21. November 2020 um >>>>> 16:09:22 UTC+1: >>>>> >>>>>> Ooops, after 10 mn the 2 values have diverged (only 1 mbar) >>>>>> The explanation is that weatherlinkliveudp driver uses "altimeter" >>>>>> and WLLDriver uses "barometer" for the station info >>>>>> >>>>> >>>>> That I do not understand. Does the driver only retrieves the readings >>>>> from the hardware, doesn't it? So, which way the driver can influence >>>>> which >>>>> values is displayed? >>>>> >>>>> >>>> >>>> There are two pressure-related elements provided by the Davis hardware. >>>> One is the pressure as reported by the sensor, the other is the pressure >>>> corrected to sea-level pressure based on your altitude. The driver code >>>> defines which sensor values it uses for what generic weewx database element >>>> >>>> Both drivers map 'bar_absolute' from the hardware to weewx 'pressure' >>>> in the database. >>>> >>>> But...the two drivers map 'bar_sea_level' from the hardware to >>>> different elements in weewx's database. >>>> >>>> - WLLDriver.py puts the value into 'barometer' in weewx >>>> - weatherlinkliveudp.py puts the value into 'altimeter' in weewx >>>> >>>> According to >>>> https://github.com/weewx/weewx/wiki/Barometer,-pressure,-and-altimeter, >>>> the correction math differs slightly, so I'd expect slight differences >>>> perhaps. A difference of 1 mbar to me isn't something to worry too much. >>>> You're talking 0.1 percent offset. The sensor itself isn't that precise to >>>> begin with. >>>> >>>> >>>> -- >>>> 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 weewx-user+...@googlegroups.com. >>>> >>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/weewx-user/fccfe641-03d1-473f-910a-c1f0d7aa2cabn%40googlegroups.com >>>> <https://groups.google.com/d/msgid/weewx-user/fccfe641-03d1-473f-910a-c1f0d7aa2cabn%40googlegroups.com?utm_medium=email&utm_source=footer> >>>> . >>>> >>> >>> >>> -- >>> Quel temps fait-il à Auffargis <https://meteo-auffargis.decoodt.eu> ? >>> >> -- > 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 weewx-user+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/weewx-user/c278a6af-f77f-4abc-9610-3d34bdc9a5a1n%40googlegroups.com > <https://groups.google.com/d/msgid/weewx-user/c278a6af-f77f-4abc-9610-3d34bdc9a5a1n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- Quel temps fait-il à Auffargis <https://meteo-auffargis.decoodt.eu> ? -- 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 weewx-user+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/weewx-user/CAAvt3%3DQqs2SuLr%2BiLVb2LWy%2ByUG-V8acE8F73G_bJLSyU%3DojYg%40mail.gmail.com.
