Maybe you want to explore playing your Reverie Harp tuned to A=432Hz. Or maybe you have tried to play your Reverie Harp along with another instrument but it just sounded a little off. These are both situations where you'll want to calibrate your tuner. Knowing how to calibrate your tuner is a useful skill and super easy to do. Below is a short video that shows you how to do it.
Here's a few tuners I recommend.
Great Electronic Tuner to keep in your case: Korg CA2
Some great free tuner apps for your phone:
Get a Shruti Box.