On the 22R with a HAC, I believe the HAC mechanically senses barometric pressure – more at sea level, less at 5,500 feet elevation. I don’t believe the HAC can compensate for air density, relative humidity, or ambient air temperature.
The ECU on a 22RE can make some adjustments to changes in AF created by changes in air density. However an AF gauge or meter only reads output.
Gnarls.
