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Windchill 'spikes'

Posted: Thu 02 Feb 2012 8:41 pm
by mikechristelow
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

Re: Windchill 'spikes'

Posted: Thu 02 Feb 2012 10:34 pm
by steve
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.

Re: Windchill 'spikes'

Posted: Fri 03 Feb 2012 8:55 pm
by mikechristelow
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!

Re: Windchill 'spikes'

Posted: Fri 03 Feb 2012 9:13 pm
by steve
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.