Tuners
General mountain dulcimer or music discussions
Why are you worried about tuner precision? Electronic turners are great for many reasons, including letting folks "tune up" backstage to the same note, instead of devoting a minute or so of on-stage time, but in my opinion, a few cents difference doesn't really matter.
In the real world when you take your dulcimer out of its case and try a tune it may sound fine, but the happy person next to you sounds out-of-tune. You get out your tuning meter and find you are a bit off because your strings are at a different temperature than they were the last time you played. In the old days, you would have said to the leader "Play me a D," and tuned to that, the group being more important than you.
Tune your middle A string as precisely as possible (in the green) and then test the tuning when you finger at frets, 3, 7, and 10. On many, perhaps most, dulcimers you will find you are a few cents sharp, but when you play music it sounds fine.
If you put your finger on the string and check the tuning, you may even find that it makes a difference where and how you place your finger.
On large organs, pairs of pipes are tuned with one a few cents sharp to produce a voice called Celeste, or a few cents flat to produce a voice called Humana. Slight dissonances make music more interesting.
As the old saying goes, "This ain't rocket science."