Hi,

I noticed to day that I am getting rain rate readings but no rainfall. Can
anyone explain this?

Raymond

"Raymond Jeffery" wrote in message
...
Hi,

I noticed to day that I am getting rain rate readings but no rainfall.
Can anyone explain this?

Raymond


This suggests that the problem is not with the station but with the console
as the only way rain rate can be calculated is from rain data received from
the station unless the rain calculation routines within the console are
faulty in some way.

It might be worth tipping the bucket on the gauge by hand several times in a
minute and viewing the data on the console to see if the rain rate readings
are in line with the number of tips.

A possible solution is to reboot the console after downloading all of the
data held on the logger assuming that you have one) as long as you have
eliminated the ISS as the source of the problem.

Alan

In message , Alan Gardiner
writes


"Raymond Jeffery" wrote in message
...
Hi,

I noticed to day that I am getting rain rate readings but no rainfall.
Can anyone explain this?

Isn't it something to do with the rain rate being an average figure so
that even when rainfall has stopped, for a few minutes afterwards you
will see the figure gradually diminish to zero.
--
Zak

"Zak" wrote in message
...
In message , Alan Gardiner
writes


"Raymond Jeffery" wrote in message
...
Hi,

I noticed to day that I am getting rain rate readings but no rainfall.
Can anyone explain this?

Isn't it something to do with the rain rate being an average figure so
that even when rainfall has stopped, for a few minutes afterwards you will
see the figure gradually diminish to zero.
--
Zak

I inferred from the original post that the rain reading was zero but there
was a rainfall rate figure; if this assumption was incorrect then your
explanation is definitely a possibility.

However it takes a reasonable time for the umbrella to vanish after it has
actually stopped raining and I think it is likely that the rainfall rate
will show zero before this symbol vanishes but I am not 100% certain of this
in all cases. Your observation about the figure diminishing to zero is
correct as the rain stops is correct as I have seen this happen many times.

Alan

Davis Application Note 28 says:

RAINFALL RATE
Parameters Used: Rain Total (actually, rain rate is a measured
variable in the sense that it is measured by the ISS and transmitted
to the display console, whereas all other calculated variables are
determined by the console from data received from the ISS.)

Formula:
Under normal conditions, rain rate data is sent with a nominal
interval of 10 to 12 seconds. Every time a rain tip or click occurs, a
new rain rate value is computed (from the timer values) and the rate
timers are reset to zero. Rain rate is calculated based on the time
between successive tips of the rain collector. The rain rate value is
the highest rate since the last transmitted rain rate data packet.
(Under most conditions, however, a rain tip will not occur every 10 to
12 seconds.) If there have been no rain tips since the last rain rate
data transmission, then the rain rate based on the time since that
last tip is indicated. This results in slowly decaying rate values as
a rain storm ends, instead of showing a rain rate which abruptly drops
to zero. This results in a more realistic representation of the actual
rain event. If this time exceeds roughly 15 minutes, than the rain
rate value is reset to zero. This period of time was chosen because 15
minutes is defined by the U.S. National Weather Service as
intervening time upon which one rain "event" is considered separate
from another rain "event". This is also the shortest period of time
that the Umbrella will be seen on the display console after the onset
of rain.

(Apologies if the line length isn't consistent above - copied from a
PDF document.)

John Dann
www.weatherstations.co.uk

John,

Thank you for info. I am reassured that all is OK. Did you find any more
info about Heat and Humidity sensor failure?

Raymond

"John Dann" wrote in message
...
Davis Application Note 28 says:

RAINFALL RATE
Parameters Used: Rain Total (actually, rain rate is a measured
variable in the sense that it is measured by the ISS and transmitted
to the display console, whereas all other calculated variables are
determined by the console from data received from the ISS.)

Formula:
Under normal conditions, rain rate data is sent with a nominal
interval of 10 to 12 seconds. Every time a rain tip or click occurs, a
new rain rate value is computed (from the timer values) and the rate
timers are reset to zero. Rain rate is calculated based on the time
between successive tips of the rain collector. The rain rate value is
the highest rate since the last transmitted rain rate data packet.
(Under most conditions, however, a rain tip will not occur every 10 to
12 seconds.) If there have been no rain tips since the last rain rate
data transmission, then the rain rate based on the time since that
last tip is indicated. This results in slowly decaying rate values as
a rain storm ends, instead of showing a rain rate which abruptly drops
to zero. This results in a more realistic representation of the actual
rain event. If this time exceeds roughly 15 minutes, than the rain
rate value is reset to zero. This period of time was chosen because 15
minutes is defined by the U.S. National Weather Service as
intervening time upon which one rain "event" is considered separate
from another rain "event". This is also the shortest period of time
that the Umbrella will be seen on the display console after the onset
of rain.

(Apologies if the line length isn't consistent above - copied from a
PDF document.)

John Dann
www.weatherstations.co.uk