What is timegrapher?

A timegrapher is a device used in horology to measure and analyze the performance of mechanical watches. It measures various parameters, such as the rate of the watch, amplitude, beat error, and positional error. These parameters help determine the accuracy and functionality of the watch. The timegrapher uses a microphone to detect the sound of the watch's ticking and converts it into a visual representation of the watch's performance on a graph. The device is a valuable tool for watchmakers and collectors to assess and adjust the performance of watches to ensure they are running correctly.