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The COSC and its laboratories comply with a Quality Manual (according to ISO 17025 & 17065) whose content and application are governed by the Swiss Accreditation Service (SAS). They are subjected to regular control audits.

None. The COSC is the repository of analytical results that belong to its customers (the watch brands). It does not have the authority to disclose information to anyone other than the legitimate owners of those results. The buyer should contact the head office of the brand to which the chronometer belongs.


No Documents issued by the COSC are optional. It is for brands themselves, and only them, to decide whether or not to communicate the results obtained during certification of the movement or watch by the COSC.


A COSC certificate is considered be a valuable document. The COSC is authorised to issue only one copy of a certificate, bearing the word ‘duplicate’. In case of loss of a duplicate, the only way to obtain a new document is to subject the watch to a new control. In this event, only the brand may request this service. The head office of the brand that has marketed the chronometer must therefore be contacted directly.


The damaged certificate must be returned to the brand that marketed the chronometer. The brand alone may obtain a new original certificate (without duplicate) by returning this document to the COSC.


Yes, a chronometer may be subject to as many controls as necessary, especially if major components of the movement have had to be replaced. However, only the brand may request this service.


The chronometer label can be compared to a university degree. At one point in its life, the candidate has proved on the basis of an examination that it has met the performance criteria that allowed them to bear the label. As for a graduate, this title is acquired for life, even if their performance is liable to change somewhat over time.



The results for to a chronometer are kept for 10 years, from the day of the end of the tests. Beyond this period, no more information can be issued about a chronometer.



The cost of monitoring by the COSC is reasonable. However, as with driving tests, it is not the exam that is expensive, but all the time and effort invested in attempting to pass. In the case of a chronometer, its design, manufacture, assembly, adjustment, and all component and movement checks required to meet the required precision require much more care and time. It is therefore the intrinsic quality of the product that justifies its price.

No, because the components of a chronometer are of superior quality and the care given to its assembly and adjustment is incomparable.

Accreditation = confirmation and recognition of technical competence

Third Party Confirmation (SAS), formally recognising that a Conformity Assessment Body (COSC) has the competence to perform specific conformity assessment tasks.

Certification = confirmation of fulfilment of prescribed requirements

Procedure whereby a third party (the COSC) confirms in writing that products, processes, systems or persons comply with the prescribed requirements (ISO 3159 in this case).