Page 1 of 1

Rainfall rate decimal place? **solved**

Posted: Tue Mar 11, 2008 7:59 pm
by skyewright
We have had approx 4mm of rain within the last hour.

\"Sensors\" shows \"PCR800 22 sec 381.0mm/h\"

[actual_rain0_rate_mm] gives 38.1 mm

Should both of those perhaps be 3.8mm?

Re:Rainfall rate decimal place?

Posted: Tue Mar 11, 2008 11:13 pm
by admin
The display on the \"sensors\" page is factor 10 too high. will be fixed with the next update.

Computation of \"actual_rain_rate_mm\" seems ok to me. Do you have a calibration factor applied?

Re:Rainfall rate decimal place?

Posted: Tue Mar 11, 2008 11:38 pm
by skyewright
admin wrote:The display on the "sensors" page is factor 10 too high. will be fixed with the next update.

Computation of "actual_rain_rate_mm" seems ok to me.
That surprises me.
A rate of 38mm/h would be an amazing downpour!
Do you have a calibration factor applied?
No calibration factor.

We did have approx. 3.8mm of rain during that hour (confirmed by other means), so 3.8mm/hr makes sense, whereas 38mm/hr is unrealistic.

I've been trying to make sense of the value shown as 'rain rate' in the dashboard and [actual_rain_rate_mm] for a few days and was meaning to ask about it. Then I noticed a possible way to make sense if perhaps the decimal place were shifted. With that change the figure does seem to correspond to the actual rate during the last hour.

Please take another look at this to double check the logic of the current interpretation.

Re:Rainfall rate decimal place?

Posted: Wed Mar 12, 2008 12:58 am
by skyewright
I just did a cross check with the rate shown on the WMR200 console. Currently the figures are:

Console: 0.8mm/hr
[actual_rain_rate_mm] 7.6 mm/hr
Sensors: PCR800 31 sec 76.0mm/h

Re:Rainfall rate decimal place?

Posted: Wed Mar 12, 2008 8:44 pm
by admin
Hi,
I did another check and it turns out that my interpretation of the wmr100/200 rain rate readings is factor 10 wrong. values are given in 1/10 inch/hour instead of 1/100 inch/hour. Will be fixed with the next update.


UPDATE:
other tests i just did, indicate that at least with the wmr-100 interpretation of sensor readings is fine... it will take some more inspection on this as i woul dlike to be 100% sure before changing things in the data logging. stay tuned...

Re:Rainfall rate decimal place?

Posted: Thu Mar 13, 2008 11:23 am
by skyewright
Boris now has these details, but for other peoples information, I have WMR200 & WMR928, both feeding Meteo hub via RFXCOM. The gauge that I observed the problem with was the WMR200 (the WMR928 gauge is under cover at least until the weekend, so it is receiving no rain at the moment).

Re:Rainfall rate decimal place?

Posted: Sat Mar 15, 2008 12:45 am
by admin
Update 2.1a fixes this