Measuring device for a mechanical watch

A portable device for testing a mechanical watch, configured so as to be held in the hand and kept in physical contact with the case of a mechanical watch, wherein the device comprises:

• a contact microphone comprising a contact piece and a piezoelectric element, for detecting the noises of the impulses generated by the movement of the watch, when the contact piece is held in physical contact with the case of the watch,
• a microprocessor configured so as to calculate, based on the signal generated by the microphone, the values of one or more parameters characterizing the operation of the movement of the watch, in addition to a memory for recording said values,
• a screen configured so as to display at least said values, and
• an electrical power source for powering at least the microprocessor, the memory and the screen,
• wherein said device includes an outer casing, a frame inside the outer casing, and wherein the contact piece has a curved external contact surface configured so as to be placed in contact with the watch case, the contact piece being attached to the frame, such that the curved surface projects at least partially from the outer casing when the device is not in use, wherein the entire external contact surface has a curved surface,
• wherein the contact piece comprises an elevation surrounding a cavity into which the piezoelectric element is provided,
• wherein the contact piece is attached a first inner flange of the frame though a compressible washer,
• wherein the microprocessor is provided on a circuit board attached to a second inner flange of the frame,
• wherein a hollow space is provided between the contact piece and the circuit board, and
• wherein the curved surface, which projects at least partially from the outer casing, is configured to allow the compressible washer to compress when a contact force between the portable device and the watch is applied.