For this case, please refer to the tutorial video below or click Air 2 User Manual to learn more.
To check the balance of roll and pitch, turn the gimbal off, and put it on the desk or ground:
If the pitch axis is balanced well, when you move the came, it can keep still in any direction.
If the roll axis is balanced well, when you turn the roll axis, the camera can keep still in any direction, no wiggle or spinning.
To check the balance of yaw, turn the gimbal off and pick it up with your hand. Tilt 45 degrees and the camera can keep still, with no wiggle or spinning.
Hope it helps.