Tuning the open strings – except for the A string – to an ordinary chromatic tuner will not work with a True Temperament guitar, as the open strings are not tuned in equal tempered intervals. Non programmable tuners can be used to a certain point. For instance like this: Tune  A on all strings: 5th fret on the low E-string.  A on the open 5th string and the 12th fret. 7th fret on the D-string. 2nd fret and 14th fret on the G-string. 10th fret on the B-string. 5th fret on the high E-string. If all octaves sounds the same, your instrument is well intonated.