Recommended Davis logger interval

[Jim Brown]

Steve. I was sure I had seen several post where you recommended 5 mi for the Davis logger interval but now can not seem to find them. I do find several places where you say that the logger and cumulus intervals should be the same. So other than being the same do you have a recommend interval?

[steve]

It really depends on how much you depend on the logger data. I run Cumulus all the time, so only need the logger data when we have a power cut. I use a 5 minute interval, which seems like a good compromise. I'm unlikely to need more than 8 days of logger data, but if I were to use a 1 minute interval, I'd be worried that our power might be off for longer than the 42 hours which that would allow for.

[dagsvic]

Hi Steve,

I previously had WL with my Vantage PRo 2 IP Data Logger..
I have it set to 30mins interval.
So i set Cumulus to 30mins as you recommended to have it the same as the logger.

If i goto change the intervals for both to be 15mins would this cause issues to current data already saved in either the IP Logger or Cumulus?

What are the benefits of having the 30 or 15mins intervals?

[PaulMy]

I had my USB datalogger and Cumulus at 30 minutes initially and later changed it to 10 minutes, which is what I still have now, and I did not see any issue with the data files in Cumulus. The monthly log file continued to show the data at the previous 30 min interval up to the time of the change and then the new 10 min interval. I also still maintain my WL data files and shut down Cumulus at about the first and middle of each month for about 5 min so I can start WL and get the data downloaded in my WL data files. The 10 min interval gives about 17 days of datalogger storage so my twice a month schedule works well. I don't know about the IP logger but expect it to give the same results.

The 30 min interval just seemed too long of a period between data and am worried that the 1 or 5 min interval was too short of a time before the logger would overwrite for those times that I might be away or that the power might be off during a winter storm, so decided on 10 min.

Paul

[steve]

As Paul says, there are no long-term issues caused by changing the logger interval. Using an interval of 30 minutes means that in future you will know what happened on the hour and half past the hour, but not what happened in between those times. This may not be of concern to you; it's entirely up to you.

[dagsvic]

Thanks both of you..
I have Downloaded Data with WL..
Then updated to 15min Intervals..
I then changed Cumulus to 15min also..
Lets see how it goes..
I did make backups before i modified though (as you always should)...
Cheers

Edit: when i D/L with WL.. it stated from 18-Sept till 25-Oct it used 67% storage for 30min intervals on the IP Logger. (345 Pages with 5 records per page.. if that makes any sense..)

[PaulMy]

Edit: when i D/L with WL.. it stated from 18-Sept till 25-Oct it used 67% storage for 30min intervals on the IP Logger. (345 Pages with 5 records per page.. if that makes any sense..)

That looks about right. From my WL download observations 99% = just over 500 pages. Your 345 pages (67%) at 30 min interval would be about 36 days of storage that was on your data logger which is about right for your Sep 18 - Oct 25 period (about 51 days for full capacity). Your new 15 min interval will give you half the days of storage, but no worries, Cumulus will just keep on recording your data and doing its thing on its own.

Enjoy,
Paul

[archae86]

If you are away from your computers for extended periods, a longer logging interval might help avoid data gaps.
In my case, I use a 5 minute interval because I like the relatively high resolution that provides on graphs. But I briefly stop Cumulus once every few days and run Weatherlink so that I have an alternate set of archived data (and Cumulus and WeatherLink have somewhat different strengths in viewing the old data).

At the 5 minute interval, I have about 10 days storage in the dongle, so if I fail to do my "stop and update Weatherlink" for more than 10 days, there is a gap in the WeatherLink data.

If my host computer crashes, and I don't get home for more than 10 days, then there is a gap in both the WeatherLink and the Cumulus data.

On reflection, I think I may go to the next longer interval than 5 minutes.