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Certificates

For timekeeping instruments that pass the tests, the COSC issues a collective certificate under the official seal, with the option of an individual operation certificate or an individual inspection certificate.

The collective certificate (Appendix Ia of the COSC General Conditions) is dated and signed by the head of the OL. It lists the results obtained for timekeeping instruments of the same category belonging to the same series and the same applicant. It contains:

  • the unique number of the collective certificate
  • the chronometer's control number
  •  the brand name on the watch and the details necessary to identify the source of the submission
  • the reference of the calibre, its type, category and specificities
  • the dates of submission and the end of the tests
  •  the measurement method used
  • the place and date of issue of the bulletin
  • the COSC seal of the observation laboratory and the signature of the laboratory manager
  • the uncertainty of measurements
  • the unique number of each movement
  • the statuses, the daily rates and the results obtained in the various criteria, including failures
  • the collective certificate statistics, as well as the summary of failures

The optional documentary report, (Appendix Ib of the COSC General Conditions, A4 format or 3 pages), dated and signed by the COSC management and detailing the results of all the tests, contains:

  • the chronometer's control number
  • the unique number of the chronometer or chronometer movement
  • the reference of the collective certificate number
  • the category, specificities, and dimensions of the movement
  • the brand name on the watch or timekeeping instrument
  • the operation statement, the results obtained in the various criteria and the date of completion of the tests,
  • the testing location
  • the issue date of the report, bearing the COSC seal of the observation laboratory and signed by the COSC management.

The certificate of individual control (Appendix Ic of the COSC General Conditions, strip format), dated and signed by the COSC management, not specifying the results obtained, contains:

  • the chronometer's control number
  • the unique number of the chronometer or chronometer movement
  • the brand name on the watch or timekeeping instrument
  • the COSC seal of the OL, the reference of the collective certificate number and the signature of the COSC management 

On request, any purchaser of a chronometer may request the results obtained by their timekeeping instrument by contacting the brand, which is the exclusive holder of the information.

Download the Terms and Conditions.