if you know time and are trying to fit rise and ambient, then the
function is linear in the unknowns and you can simply use SLOPE and
INTERCEPT (or LINEST, if you prefer). In that case, your X column for
fitting would be the calculated value =1-exp(-time)

Jerry

mcgradys wrote:

Hi all,

Newbie to this forum, but need some excel help. I have collected a
bunch of data from an object as it heats up. The curve is very similar
to a capacitor charging current curve. In my case, manually trying to
approximate this curve, I come up with a formula of y=
(rise)*(1-exp(-time))+ambient. Is there a way in excel to fit a curve
like this or do I need an aftermarket solution? I need something that
will use the data points and perform calculations to determine the
curve.

Thanks,

Sean