Originally Posted by mrphotoman
or go to weather.gov and you can see it for your area there live.
how do you calculate it using a barometer reading?
if you go to noaa they have calculators... it should read some thing like 30.XX or around there in inches of mercury... different than psi... its like when the car is vacume thats also in inches of mercury.
so like 30.xx in of mercury = 14.X psi.. thus using that number for your calulations...
this is how we calibrate some of our instuments at work.