Pendulum is the first type of resonator used in watchmaking. Although it can be extremely precise, it has the defect of not being able to be transported on the move.

There are two reasons for its potential high precision. One is that it can be large and the other is that these timepieces remain stationary and do not suffer shocks.

The speed of this resonator is regulated by its length. When you shorten it, it will go faster and when you lengthen it, it will go faster. Just like a ruler that you vibrate on the corner of a table.

The pendulum often reaches its highest precision in observation pendulums called regulator, this is due to thermal compensations on the pendulum.