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5.5 Calibration or Rain totals
When on the “Live Data” screen, you can press the “More” button (upper
right) to enter the calibration screen or the rain totals screen.
When you select “Calibration” you can change sensor calibration values on
the next screen.
If you tap on “Rain Totals” instead, you can edit the rain total for the current
day, week, month, or year. This is useful when you start using this system
instead of another one that has accumulated data, or simply if you know the
values to be incorrect.
5.5.1 Calibration of barometric pressure settings.
Calibration of barometric pressure requires some additional understanding,
which we will provide here. Also provided is a step by step procedure for
calibrating correctly.
Absolute barometric pressure, can be calibrated at manufacturing time by
comparing with a precise instrument that measures pressure at the same
location. In practice, sometimes small adjustments of a few hPa may be
needed. The relative pressure represents what the air pressure would indicate
if your station was at sea level and depends on the altitude of your gateway
and cannot be known in advance. This is why it needs an adjustment.
There are different manners in which to handle this adjustment. We will
outline a reliable procedure below, which requires adjusting both pressures.
The method assumes that you have an official airport sufficiently nearby to
act as a reliable reference. Usually distances of up to 25 miles work reliably,
but this is not always true and depends on geography. We start by assuming
that your station’s absolute pressure reading is correct and needs no offset
correction.
The procedure below assumes you are starting from the gateway’s factory
setting. With those settings, ABS and REL should, at this time, be
displaying the same value. We also assume, for the moment, that ABS
pressure is 100% correct.
Summary of Contents for GW1001
Page 26: ...26 Figure 14 Weather Services uploading setting screen ...
Page 30: ...30 Graph display List display ...
Page 42: ...42 You may view your weather station data by pressing your device on this screen ...
Page 46: ...46 https itunes apple com us app pws weather station monitor id713705929 ...
