Στάλθηκε από: george_
« στις: Απρίλιος 16, 2014, 22:18:53 μμ »
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1. It is essential for a piece to meet seven criteria: average daily rate, mean variation in rates, greatest variation in rates, difference between rates in horizontal and vertical positions, largest difference in rates, thermal variation and rate-resumption.
2. Minimal requirements in seconds per day (s/d), category 1 (diameter of the movement less than 20 mm)
- average daily rate = -4 / +6
- mean variation in rates = 2
- greatest variation in rates = 5
- difference between rates in horizontal and vertical positions = -6 / +8
- largest difference in rates = 10
- thermal variation = ± 0.6
- rate-resumption = ± 5
3. Minimal requirements in seconds per day (s/d), category 2 (diameter of the movement equal or superior to 20 mm)
- average daily rate = -5 / +8
- mean variation in rates = 3.4
- greatest variation in rates = 7
- difference between rates in horizontal and vertical positions = -8 / +10
- largest difference in rates = 15
- thermal variation = ± 0.7
- rate-resumption = ± 6
4. Chronometer’s uniqueness: a serial number is engraved on the movement as a certification number will be given to the movement that passed the tests.
