Gw1000 produces 2 pressure readings: As defined by Ecowitt Calibration of barometric pressure settings <http://www.ecowitt.com/news/102.html> *Absolute Pressure* "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" *Relative Pressure* "The relative pressure represents what the air pressure would indicate if your station was at sea level and depends on the altitude of your console and cannot be known in advance. This is why it needs an adjustment"
If you work your way thru there cal procedure you will see that you use the WS View app to set 2 offsets: Abs Offset Rel Offset To set Rel Offset they have you determine station elevation and direct you to a site that produces a offset based solely on elevation. So *Rel Offset* is a *STATIC *offset applied against your Absolute Pressure. It never changes if we set a Rel Offset of 6.0 hPa then Relative Pressure will always read 6.0 hPa higher than Absolute Pressure. As we see in WeeWX Wiki Station or Gauge Pressure (key *pressure*): This is the absolute, raw pressure as measured by your instrument. It is not corrected for altitude or pressure. Pilots call this QFE Sea-level Pressure (*barometer*): This is the pressure corrected for altitude, temperature, and (frequently) humidity. Pilots call this QFF. This is the value displayed by the standard skin. Altimeter Pressure (*altimeter*) : This is the pressure corrected for altitude, using a standard temperature profile. Pilots call this QNH. Because we are on a very limited device which does not attempt in any way to apply a temperature compensation I believe that mapping 'altimeter': 'relbarometer' may be more appropriate. StdWXCalculate will calculate barometer for us when it appears in a template. Thanks Paul' -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to weewx-user+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/weewx-user/935bed8d-3c63-4f6b-bdde-1c358735e449n%40googlegroups.com.
