Glossary

refers to the push or force required to maintain the oscillation of the balance wheel in a mechanical watch. The balance wheel, along with the hairspring, regulates the accuracy of time display in the watch. The impulse is provided by the escapement mechanism, which interacts with the balance wheel, allowing it to move forward and then releasing it at the right moment for it to swing back (oscillate back and forth).

Watchmakers focus on designing, adjusting, and lubricating the escapement mechanism to improve the impulse and achieve good timekeeping performance.

Quartz watches do not rely on impulse as they use a different mechanism based on the oscillation of a quartz crystal.