[wxsig] BP calibration (was T-238 Humidity Calibration)

[Robert McGwier]

Ooops.   I just took the title of the note, obviously what I said below 
applies to the calibration of ALL sensors and in particular to the BP.  
If you can take measurements of known conditions, you can derive the 
transfer function in software and not need to twiddle pots.

Bob
N4HY


Robert McGwier wrote:

> Will:
>
> Since you are using the 68HC908, I do not understand why serious 
> tinkering with pots are necessary.   If you measured the sensor 
> outputs with a sufficiently dense set of points (and this cannot be 
> that many),  an approximation to the exact "transfer function" from 
> humidity reading to actual humidity should be easily derived.  The set 
> of points stored and then all readings are run through this 
> "calibration engine" to produce the actual reading.
>
>
> What am I missing?
>
> Bob
> N4HY
>
>