The term “amplitude” often surfaces in discussions about mechanica

The term “amplitude” often surfaces in discussions about mechanical watch malfunctions and repairs. At the heart of a mechanical watch’s movement lies a resonator composed of a balance wheel and hairspring, whose oscillation cycle’s stability determines the watch’s timing accuracy. The oscillation of the balance wheel, swinging back and forth, defines the amplitude, which is also referred to as the “swing” in the watch industry. By definition in physics, amplitude is the maximum displacement of an oscillating body from its position of equilibrium.

The amplitude of a watch is always in flux, influenced by numerous factors. Primarily, it is determined by the tension of the mainspring; a fully wound mainspring results in a higher amplitude. Additionally, friction between the balance wheel’s pivots plays a role. As the watch’s position changes, so does the orientation of gravity on the balance wheel’s hairspring and the friction conditions of the wheel’s pivots. Notably, there is a significant difference in amplitude between when the watch is in a horizontal position and when it is vertical, with the vertical amplitude typically being around 40 degrees lower than when the watch is lying flat.

Several other factors can impact the amplitude, including the watch’s design, lubrication state, axial and radial clearance of gears, and the consistency of the mainspring’s torque output. These elements are crucial for watchmakers and repair technicians to consider when diagnosing and addressing issues with a mechanical watch’s performance. Ensuring optimal amplitude is key to maintaining precision in timekeeping, highlighting the intricate balance and engineering prowess embedded in the art of horology.