Data Interval and Wind Gust Speed Measurement

[Station House]

Some advice please.

I beleive the Fine Offset unit transmits data every 48 seconds.

Cumulus has options for setting the data interval for 1 min, 5 min, 10 min etc.

I initially set mine at 10 minutes - no idea why, I guess it seemed a good idea at the time!

The last couple of days (it's been somewhat breezy here in Scotland) I've noticed that the peak wind gust has not exceeded 18.1 mph - that may be correct as the sensor is not mounted as high as ideally it could be, but it's felt somewhat faster standing outside!!!

Does Cumulus look at the Fine Offset data for the last 10 minutes and identify the 'peak' wind speed over the last 10 minutes, or does a peak gust need to coincide with the 10 minute interval to be logged?

Any pitfalls from now changing the data interval in Cumulus to 1 minute?

Thanks all

[steve]

Does Cumulus look at the Fine Offset data for the last 10 minutes and identify the 'peak' wind speed over the last 10 minutes,

Yes.

Any pitfalls from now changing the data interval in Cumulus to 1 minute?

I usually suggest that you have the Cumulus interval set to the same as the station interval, just so that your logs always have approximately the same interval whether it's live data or logger data, but it's not essential.

[steve]

Does Cumulus look at the Fine Offset data for the last 10 minutes and identify the 'peak' wind speed over the last 10 minutes,

Yes.

This of course assumes that Cumulus is actually running. If the data is coming from the logger, then the values are just those which were current at the time they were left in the station logger.

[Station House]

Thanks Steve

As I'm not currently uploading to a website I tend to just upload data to Cumulus each evening to provide me with historic data trends and a more comprehensive view than the W8681 LCD Panel displays 'at a glance'.

I hope that I am therefore correct in interpreting that the Cumulus data interval shouldn't make a lot of difference, as the data is dependant on whatever the Fine Offset Receiver has logged throughout the day.

[steve]

I hope that I am therefore correct in interpreting that the Cumulus data interval shouldn't make a lot of difference, as the data is dependant on whatever the Fine Offset Receiver has logged throughout the day.

That's correct; data taken from the logger is put into the Cumulus logs at the same interval as it was logged, i.e. one station log entry = one Cumulus log entry.

But this probably explains why you're not seeing the peak gusts that you expect; the station has forgotten them. So the correct answer, in your case, to your original question should actually be that the peak gust has to coincide with the (station) logger interval.

[Station House]

Thanks Steve - makes sense

From other posts I think you may be able to change the Fine Offset Units logger interval - I'm not 100%.

Think I'll try closing Cumulus, reinstalling Easy Weather and seeing if there are any settings I can change.

Will report back!

[steve]

From other posts I think you may be able to change the Fine Offset Units logger interval

Yes, you can change it with Easyweather. 10 minutes is the minimum.

[Station House]

Thanks - that's the 2 min interval plan dashed

Does that mean that also having Cumulus running at 10 minutes is the best approach?

[steve]

I'd have them set to the same interval just to be consistent, but it's not critical. Someone who was running Cumulus most of time and not using the station logger much, might consider using a shorter interval in Cumulus.

[wd40]

As a side issue, if you have a to correct your data for some reason or another, then having shorter log interval means that many more log entry's to correct. That is the main reason I went back to 10 minutes. Might not be the best reason for longer intervals but it is something to think about.

Randy

[nking]

Yes, you can change it with Easyweather. 10 minutes is the minimum.

I think you'll find it can be less than 10 mins

[steve]

I think you'll find it can be less than 10 mins

Really? 5 minutes? I did hesitate before posting that, but somehow 10 minutes seemed right.

[nking]

Really? 5 minutes? I did hesitate before posting that, but somehow 10 minutes seemed right.

Minimum is 5 mins, the memory of the logger will hold 4080 records which means you can have a two week holiday (14.16 days) without the oldest item getting over written

[steve]

which means you can have a two week holiday (14.16 days)

Well, yes, I knew that bit, I just didn't do the sums to check that meant a 10 minute interval.

[nking]

Well, yes, I knew that bit, I just didn't do the sums to check that meant a 10 minute interval.

You mean I went to all that bother and I didn't need to get out my calculator after all .................