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Windchill 'spikes'

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mikechristelow
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Weather Station: Watson W8681 (solar)
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Windchill 'spikes'

Post by mikechristelow » Thu 02 Feb 2012 8:41 pm

Hi,

I'm pretty new to Cumulus and just started with a TechnoLine 2350 (which I suspect is a re-badged LaCrosse) in January.

I've learnt quickly that a USB connection to the PC is a poor substitute for a proper serial connection (now addressed), and equally quickly that the fantastic "unshielded" sensor cables supplied with the station attract considerable interference (having fitted ferrite beads, now under observation).

All told, Cumulus seems very solid whilst the TechnoLine 2350 seems a bit iffy, but I'm not going to be able to trade-up for a while (as it was a christmas present from the wife :P ).

Can enyone explain the bizarre behaviour I get on my Trends | Outside Temp graph, where I get periods of (evidently) no windchill and then bursts of very spiky windchill readings - see the attached pic.

Many thanks,

Mike
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http://www.christelow.co.uk
“It's snowing still," said Eeyore gloomily.
"So it is."
"And freezing."
"Is it?"
"Yes," said Eeyore. "However," he said, brightening up a little, "we haven't had an earthquake lately.”


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steve
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Re: Windchill 'spikes'

Post by steve » Thu 02 Feb 2012 10:34 pm

Wind Chill doesn't apply at wind speeds of under 4.8 kph, so I assume that's what you're seeing, assuming you have Cumulus calculating the wind chill.
Steve

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mikechristelow
Posts: 165
Joined: Wed 01 Feb 2012 9:33 pm
Weather Station: Watson W8681 (solar)
Operating System: Windows XP SP3
Location: Crewe, Cheshire
Contact:

Re: Windchill 'spikes'

Post by mikechristelow » Fri 03 Feb 2012 8:55 pm

Thanks Steve.
The spikes seem to correlate with wind speed above the 4.8kph mark so that would seem to explain things. However, in the Station settings in Cumulus I have the checkbox for Calculate WindChill unchecked so was assuming there would be no plot on the graph for this!
http://www.christelow.co.uk
“It's snowing still," said Eeyore gloomily.
"So it is."
"And freezing."
"Is it?"
"Yes," said Eeyore. "However," he said, brightening up a little, "we haven't had an earthquake lately.”


User avatar
steve
Cumulus Author
Posts: 26717
Joined: Mon 02 Jun 2008 6:49 pm
Weather Station: None
Operating System: None
Location: Vienne, France
Contact:

Re: Windchill 'spikes'

Post by steve » Fri 03 Feb 2012 9:13 pm

In that case the value is coming from the station, and it must be applying the same rule. If you want to remove wind chill from the graph, right-click on it.
Steve

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