FAQ: Difference between revisions

60 bytes added ,  12:50, 3 January 2012
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== Cumulus doesn’t show the same pressure as my Fine Offset console  ==
== Cumulus doesn’t show the same pressure as my Fine Offset console  ==


First of all, check that you are comparing the Cumulus display with the ‘relative’ pressure on your console. Cumulus displays pressure corrected to sea level, which the console calls ‘relative pressure’. Make sure that you have set your console's relative pressure correctly.
First of all, check that you are comparing the Cumulus display with the ‘relative’ pressure on your console. Cumulus displays pressure corrected to sea level, which the console calls ‘relative pressure’; it displays the letters "rel" when this is being displayed. Make sure that you have set your console's relative pressure correctly.


If your relative pressure still disagrees with the Cumulus display, it may be due to the following: The Fine Offset stations only supply absolute/station pressure to Cumulus, so it has to adjust to sea level. When Cumulus starts, it reads the pressure ‘offset’ (the difference between absolute/station and relative/sea level pressure) from the station so it can use it subsequently to calculate the sea level pressure. Sometimes the offset that is read is clearly garbage, so Cumulus uses zero as a best effort.  
If your relative pressure still disagrees with the Cumulus display, it may be due to the following: The Fine Offset stations only supply absolute/station pressure to Cumulus, so it has to adjust to sea level. When Cumulus starts, it reads the pressure ‘offset’ (the difference between absolute/station and relative/sea level pressure) from the station so it can use it subsequently to calculate the sea level pressure. Sometimes the offset that is read is clearly garbage, so Cumulus uses zero as a best effort.