.. just a mention for those who dont yet know..
that for tuning harps [for me - autoharps / pianoharps / dulcimer].. and any other awkward string instruments..

you can buy accesory leads that plug into elecronic tuner,
these leads have contact piezo pickups built into rubber suction caps to attach temporarily to body of instrument while tuning..
also similar leads with pickups that attach to instrument with mini plastic sprung clips..

[similar principle to those popular stage tuners that clip to head of guitar..]

if i can find mine i'll let you know the brandname..