Request spot pressure precision of 0.1 hPa.
This post is deleted!
If you change units to in. Hg you'll have "precision" of 1/100 of an inch.
In my opinion calibrating a barometer with pressure readings from forecast models
is not a good practice.
Even for the same location, pressure from two models may vary a lot!
Which one will you take as correct?
The standard procedure is to calibrate it with measurments from a nearby official
meteorological station (e.g. airport) because they use high precision barometers
which calibrate at regular intervals.