One problem with using an electronic tuner is that they sometimes respond to harmonic vibrations, so it may show the note as F when the string is actually a B note. Not difficult to work around, but you do need to actually LISTEN to the notes.
I think our tuner is an Intelli tuner.
If looking to buy a clip on, I would advise actually trying one on your instrument before purchaase.

If the instrument hasn't been used for a long while,the stings may need replacing, but if they have been kept dry, may still be okay.
Quack!
GtD.