Before applying any offsets, switch the weather system to display pressure in hPa, as it is more precise.
Once the weather station is calibrated, the unit can be changed back to inHg if preferred.
Depending on the weather station, the offsets need to be applied differently.
WS-2000 / GW1000:
The offset adjustments for Step 1 and Step 2 need to be done separately.
Make the change for Step 1, then exit out of the calibration settings.
Then re-enter the calibration settings for Step 2.
Failure to do so will result in errors, as the system does not save the offset adjustment without leaving the calibration settings.
WS-2902: For Step 1, the offset needs to be applied to the relative pressure. For Step 2, the offset needs to be applied to the absolute pressure.