ISO 3159 - Chronometer
ISO 3159 standard defines the features of the chronometer - strap with balance wheel oscillator.
To be allowed to receive a formal and legal chronometer certificate, the watch requires to cover the complete accuracy criteria of this standard.
Watches are tested during 16 consecutive days according a specific protocol tray.
The ISO 3159 chronometer standard is applied on Timepieces.
Each watch is daily measured with a dedicated camera of vision.
In between 2 measures, the watch is manually wind it up and then placed in a climatic chamber (cold or warm).
To complete the protocol, a last wearing simulation is performed within 2 additional days.
To briefly summarized, 17 consecutive days of testing are required to perform the complete chronometer protocol.