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Dew Point Reporting

Discussion specific to Davis weather stations
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TwoTonTed
Posts: 46
Joined: Wed 26 Aug 2015 5:39 pm
Weather Station: Davis Vantage Vue
Operating System: Windows 11
Location: St Brides, Vale of Glamorgan

Dew Point Reporting

Post by TwoTonTed »

I've only just noticed that Cumulus (1.9.4) is no longer reporting Dew Point from my Davis Vantage Vue. I guess this is a problem with a component on the station itself? It just says that the DP is exactly the same as current temperature.

Thanks.
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ConligWX
Posts: 1831
Joined: Mon 19 May 2014 10:45 pm
Weather Station: Davis vPro2+ w/DFARS + AirLink
Operating System: Ubuntu 24.04.1 LTS
Location: Bangor, NI
Contact:

Re: Dew Point Reporting

Post by ConligWX »

HI there.

Basically Dew point is a calculation between pressure and water content of the air. is your temp sensor and air pressure sensors being reported correctly by your vantage vue?

might be worth looking at the log files too.

due point here in the UK at time or writing is actually Frost Point since most areas will be below freezing.
TwoTonTed
Posts: 46
Joined: Wed 26 Aug 2015 5:39 pm
Weather Station: Davis Vantage Vue
Operating System: Windows 11
Location: St Brides, Vale of Glamorgan

Re: Dew Point Reporting

Post by TwoTonTed »

hi, my temp and air pressure broadly agree with other stations nearby give or take 1-2 deg C and +- 5-10 mb pressure. If I look at the Outside Humidity graph, it stopped reporting a month or so ago, so guess that's a sensor problem?!
freddie
Posts: 2850
Joined: Wed 08 Jun 2011 11:19 am
Weather Station: Davis Vantage Pro 2 + Ecowitt
Operating System: GNU/Linux Ubuntu 24.04 LXC
Location: Alcaston, Shropshire, UK
Contact:

Re: Dew Point Reporting

Post by freddie »

Dew point calculation depends on RH data being available. So if your station is not reporting RH then dew point cannot be calculated.
Freddie
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TwoTonTed
Posts: 46
Joined: Wed 26 Aug 2015 5:39 pm
Weather Station: Davis Vantage Vue
Operating System: Windows 11
Location: St Brides, Vale of Glamorgan

Re: Dew Point Reporting

Post by TwoTonTed »

thanks, I'm in contact with Pro Data who supplied the hardware back in 2020 - everything has a life I imagine as I live in a very exposed coastal location in Wales!
TwoTonTed
Posts: 46
Joined: Wed 26 Aug 2015 5:39 pm
Weather Station: Davis Vantage Vue
Operating System: Windows 11
Location: St Brides, Vale of Glamorgan

Re: Dew Point Reporting

Post by TwoTonTed »

I'm told I need a new harness or station itself. That said, I have a sensor suite and harness I've kept from a previous model which I think is ok.

Is it possible to suspend the station from reporting to the console while I make the part change? Last time I did something similar I created a whole load of false data which took ages to edit out of the log files.

Thanks
freddie
Posts: 2850
Joined: Wed 08 Jun 2011 11:19 am
Weather Station: Davis Vantage Pro 2 + Ecowitt
Operating System: GNU/Linux Ubuntu 24.04 LXC
Location: Alcaston, Shropshire, UK
Contact:

Re: Dew Point Reporting

Post by freddie »

You can put the station into maintenance/setup mode - see https://www.wxforum.net/index.php?topic=18025.0
Freddie
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TwoTonTed
Posts: 46
Joined: Wed 26 Aug 2015 5:39 pm
Weather Station: Davis Vantage Vue
Operating System: Windows 11
Location: St Brides, Vale of Glamorgan

Re: Dew Point Reporting

Post by TwoTonTed »

thanks Freddie
TwoTonTed
Posts: 46
Joined: Wed 26 Aug 2015 5:39 pm
Weather Station: Davis Vantage Vue
Operating System: Windows 11
Location: St Brides, Vale of Glamorgan

Re: Dew Point Reporting

Post by TwoTonTed »

I've successfully installed a new ISS and am hoping this lasts longer then the previous 2 I've had. I seem to get about 5 years out of them before something breaks. Maybe in my climate (wet/windy/salty air for much of the year) is to blame?

Foolishly I didnt leave the new station outside before I configured it at the console. As a result yesterday's max was in the 20s lol. I've managed to edit out yesterday's rogue 'high temp' spike from, it appears, everything other than Yesterday's Recent Extreme - this is still showing the false Max Temp.

Is this just a transient value that it overridden at midnight tonight, and never used in other summary data? I also had to edit the apparent temp value as well.

Is there anything else I've forgotten?
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