Observator Instruments OMC-140, Руководство по установке

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OMC-140 Installation Manual Page 32
6.4.7 Setting up RAIN (tipping bucket)
In combination with MeteoLink the OMC-140 can calculate Rain per day and Rain intensity. It will also
keep track on the total Rain (since reset of the MeteoLink module).
You will need to enable Rain output via the web interface of MeteoLink (see the Meteolink manual).
This will result in an update message once every 10s, so the display knows a Rain gauge is connected.
MeteoLink will immediate send an update message once a pulse has been received (it won’t wait for
the 10s interval).
For using the Rain / day parameter the time must be set correct in the OMC-140. If a GPS is connected,
it will be corrected automatically, otherwise set the correct time via the USB port in the SD menu (see
chapter 7).
Also the mm/pulse must be set (default is 0.2mm) in the USB menu
The output of Meteolink is a counter. It runs from 0 to 65000. At 65000 it will be reset to 0. Also
depowering MeteoLink will reset the counter. Since the counter value will be send every 10s (or sooner
if a pulse has been received), the display will get the correct data even if a message is missed.
The OMC-140 monitors the counter and if a change is detected the Rain counter is added with
difference multiplied by the mm/pulse.
The Rain / day will be updated and the Rain intensity will be recalculated.
Rain intensity is somehow limited with use of a tipping bucket rain gauge. It will be calculated in the
OMC-140 as follows:
Once an increment in the pulse counter has been detected, the increment will be divided by the
measured time between the last and previous increment.
Formula:
Last received updated counter value – previous received updated counter value
Rain intensity = ───────────────────────────────────────────────────────────────────
Time between values
If no pulses are received the time will go up and the displayed intensity will go down.
When the MeteoLink resets – the counter goes back to 0 – nothing will change until a new pulse
(increment) has been received.
The rain intensity will not be correct until at least 2 pulses have been received!