Weather Corrections

[xxalexx at ix.netcom.com]

> OK, we have on some applications, Baro, and IAT/MAT.  During
> crank, we can sample for airtemp, and Baro.  As I recall there is
> a formula for working out humidity from that.  Is that "correction"
> used somewhere, in the gm ecms?.  They have some tables for
> baro, and temp, so would it be safe to assume that the humidity
> is worked into the corrections somewhere?.
You also need a wet bulb, vapor pressure and ferrel equations to
calculate humidity.  This is a rather long computation, I can
post the formulas if needed.  I do not think it is safe to say that 
humidity is in equations, as I do not know of any cars that have
wet bulb pyschrometers.  Some Diamler-Chrysler cars use a 
humidity sensor for interior climate control.
alex