timegrapher

A timegrapher is a specialized instrument used for measuring and displaying the rate and amplitude of a mechanical watch's balance wheel. It operates by detecting the acoustic vibrations produced by the watch's escapement mechanism. These vibrations are then converted into electrical signals and processed by the timegrapher's internal software. The output is typically presented as a graph, often referred to as a "wiggle" or "tick trace," on a screen.

The graph displays a series of vertical lines, each representing an individual tick of the balance wheel. The horizontal position of the lines indicates the timing of each tick relative to a precise reference clock. The vertical height or amplitude of the lines represents the strength of the balance wheel's swing. By analyzing these graphical representations, a watchmaker can assess various aspects of a watch's performance.

Key parameters that can be evaluated using a timegrapher include the rate deviation, which is the difference between the watch's actual timekeeping and its set rate (often expressed in seconds per day). The amplitude, a measure of how far the balance wheel swings, is crucial for understanding the watch's power reserve and its ability to maintain accuracy. The beat error, which quantifies the imbalance in the swing of the balance wheel in each direction, can also be identified. Timegraphers are essential tools for watch servicing, repair, and quality control.