How to tune the yangqin part 2/3 - The electronic tuner

In this video I explain the differences between electronic tuners and how to use them.
0:00 Intro
0:27 How to use it
3:23 External contact microphone
6:23 Smartphone or dedicated tuner ?
7:21 Smartphone apps
In the two other videos, I explain where each note is located on a modern yangqin:
Part 1 - Layout of the yangqin : • How to tune the yangqi...
And how to actually tune the instrument:
Part 3 - Tuning the instrument : • How to tune the yangqi...