Intake Air Temperature

[Frederic Breitwieser]

>         Anybody have any suggestions on how I can accurately and instantaneously
> measure intake air temperature?  I have had home thermometers suggested,

Well, your requirement if "instant" is a problem... thermistors as well
as semiconductors take a "little time" to ramp up or ramp down if the
temperature changes.  This is because the thermistors are coated with an
epoxy for strength and protection, and the semiconductors have the shell
they are mounted in as a slight insulator.  If you were to get one too
room temperature, and whip it into the freezer while attached to a VOM,
you'll the thermistor responds quickly, but not instantly.

On a forced induction car, this might be a problem because when the
boost kicks in, the air temp soars really quickly.  GM, Ford, Chrysler
use air temperature sensors that respond quickly, but also not
instantly.  Either its not "critical" to the operation of an EFI system,
or their code compensates somehow.  Hey, might considering using one of
their sensors?  Junkyard cheap too....

If you are simply trying to measure temperature in your intake while
standing next to the car, that's a different story.  You can drill a
hole, stick in a grommet, and put a mercury thermometer into that, but
again, its not the fastest responding thing in the world either.