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Rainfall readings, don't forget I am a newbe!
Posted: Sat 20 Mar 2010 8:49 am
by princejim
This morning I monitored my rainfall and it says 2090.4mm for yesterday, me thinks the decimal point is in the wrong place, how do I reset this please. Running fine offset Watson W-8681, with 1.8.9. build 927, the station panel says, easyweather says 1.8mm for yesterday?
Re: Rainfall readings, don't forget I am a newbe!
Posted: Sat 20 Mar 2010 9:03 am
by goldrush
Welcome to the Forum
Wow. even more rain than we get:-)
As your Watson is showing the correct figure open Cumulus
On main screen, Click
Configuration
Calibration
Bottom box in Multipliers section
Make sure 1.00 is entered.
1 point to bear in mind is that wind and vibration can cause the rain bucket to give false high readings (but this would also show up on your Watson display) so make certain the rain bucket is "securely nailed down":-)
Re: Rainfall readings, don't forget I am a newbe!
Posted: Sat 20 Mar 2010 9:09 am
by princejim
Thanks for the fast response. Yes did that and it was set correctly?
Re: Rainfall readings, don't forget I am a newbe!
Posted: Sat 20 Mar 2010 10:16 am
by Gina
That sort of reading can be caused by radio interference near the rain gauge (or cable). And as mentioned above, may be caused by movement of the rain gauge. All the photos etc. from the weather station distributors show the gauge mounted up the pole with the other sensors. This is just about the worst place, being very susceptible to "waggling" by the wind, giving false rain readings. I'm also perplexed by the reading not showing on the console if either of these were the cause.
As a newbie I suggest reading the other posts in this forum and others including the "Homebuilt". We have all experienced these problems and have discussed it profusely

Personally, I'm in the process of adding this sort of information to my weather website (see signature). Although I'm no longer using Cumulus (I'm a Linux buff), all the weather station info applies whatever the software (which is why I continue to read and post in these forums).
Re: Rainfall readings, don't forget I am a newbe!
Posted: Sat 20 Mar 2010 10:23 am
by steve
The Fine Offset stations are very good at creating large amounts of imaginary rainfall, which may or may not appear on the console depending on what the problem was exactly. The station has a total rainfall counter that just keeps incrementing, and Cumulus has to calculate the rain figures from that, and only that. Sometimes the counter can suddenly jump up for no reason, and sometime, and possibly worse, it can go down for a while, and then back up again. Cumulus does its best to cope, but it's quite tricky to work out what's going on and often it can't.
Correcting all of the data is a bit messy. There is some useful info here:
http://wiki.sandaysoft.com/a/FAQ#My_sta ... it_to_zero
Re: Rainfall readings, don't forget I am a newbe!
Posted: Sat 20 Mar 2010 10:46 am
by Gina
My immediate thought was "but that leaves the total rainfall wrong" but on second thoughts, it doesn't matter - the Total Rainfall is the rainfall since you started logging data which might be recently or years ago and is therefore meaningless or at least of very little value. The rainfall in each year (or month etc.) may be interesting and this "virtual rain" will upset such values - so you may wish to correct the data files accordingly. This is also covered by the Wiki I believe.
Re: Rainfall readings, don't forget I am a newbe!
Posted: Sat 20 Mar 2010 11:08 am
by apenwith
Hi
I think the fact that Easyweather and Cumulus differ in the yesterday reading might be because they are looking at different roll over times (ie the time set as the end of one day and the start of the next). I think easyweather always uses midnight and Cumulus can be set to that or nine am.
Regards
Alan
Re: Rainfall readings, don't forget I am a newbe!
Posted: Sat 20 Mar 2010 12:08 pm
by steve
Gina wrote:My immediate thought was "but that leaves the total rainfall wrong" but on second thoughts, it doesn't matter - the Total Rainfall is the rainfall since you started logging data which might be recently or years ago and is therefore meaningless or at least of very little value.
That's right, the 'total' is just an arbitrary counter that keeps going up (or not!) until I assume at some point it overflows and wraps round.
Re: Rainfall readings, don't forget I am a newbe!
Posted: Sat 20 Mar 2010 12:11 pm
by steve
apenwith wrote:I think the fact that Easyweather and Cumulus differ in the yesterday reading might be because they are looking at different roll over times (ie the time set as the end of one day and the start of the next). I think easyweather always uses midnight and Cumulus can be set to that or nine am.
There is that, yes, but there are other reasons why they could differ. Easyweather, Cumulus and the console could all show different totals depending on how exactly they work them out, and how their method is affected by the glitches in the total counter.