RCT/AURAL vs "Guitar Tooner" was Rossler

[Fred Brown RPT]

Hello,
I have been 'lurking' on this list for several years reading it as a
digest
and rarely posting.
I have a customer who has checked my tuning with a Korg something or
other
guitar tuner and has said that my
tuning is both sharp and uneven(eg A49 is sharp while C#41 is spot on).
She
apparently has been tuning her own
piano with the help of this machine for many years and I suspect that
her
ear has become accustomed to something
other than an equal temperament. I had tuned the piano 1 month before
and
upon returning it was at A440 and only
really needed to have unisons touched up (like something you would do
during intermission at a concert). I did a
full tuning however leveling some strings during my visit so I know it
was
both correct and extremely stable. Can
anyone speak to the shortcomings of these "needle" type tuners? I know
for
one that you can't control what
octave/partial they listen to but why wouldn't my tuning at least appear
to
be smooth to it...either the same sharp
or flat as you measure the temperament octave?
thank you
Fred Brown RPT
Atlanta, GA