COSC - Contrôle officiel suisse des Chronomètres
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The Swiss Watch certification for the description of "Chronometer"

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Each un-cased movement undergoes a 15 day test regime to record
changes in its daily rate (in seconds/day) in various positions and
temperatures. 

Consistency is tracked by calculating the "variance" of the same
measurement on sequential days.

Positional accuracy is calculated by comparing the rate seen in a
horizontal (less stressful) postion and a vertical (more stressful)
position.

The basic limit, the mean daily rate seen over the first 10 days
in 5 positions, is -4/+6 seconds a day. A "gaining" rate is more
acceptable then a "losing" rate.
________________________________________
|     |       |     |          |        |
| Day |Temp/°C| Pos |Daily rate|Variance|
|_____|_______|___ _|__________|________|
|  1  |    23 |  6H |      M1  |        |
|  2  |    23 |     |      M2  |     V1 | V1 = M2 - M1
|  3  |    23 |  3H |      M3  |        |
|  4  |    23 |     |      M4  |     V2 | V2 = M4 - M3
|  5  |    23 |  9H |      M5  |        |
|  6  |    23 |     |      M6  |     V3 | V3 = M6 - M5
|  7  |    23 |  Dd |      M7  |        |
|  8  |    23 |     |      M8  |     V4 | V4 = M8 - M7
|  9  |    23 |  Du |      M9  |        |
| 10  |    23 |     |      M10 |     V5 | V5 = M10 - M9
| 11  |     8 |  Du |      M11 |        |
| 12  |    23 |  Du |      M12 |        |
| 13  |    38 |  Du |      M13 |        |
| 14  |    23 |  6H |      M14 |        |
| 15  |    23 |  6H |      M15 |        |
|_____|_______|_____|__________|________|

Du = Dial Up           (Horizontal position)
Dd = Dial Down         (Horizontal position)
3H = 3 Up (crown up)   (Vertical position)
9H = 9 Up (crown down) (Vertical position

_________________________________________________________________
|                        |    |                         |        |
|      Test              | ID |Description              | Limit  |
|________________________|___ |_________________________|________|
|                        |    |                         |        |
|Mean Daily Rate M(1->10)|  M | average of M1 > M10     | -4/+6  |
|________________________|____|_________________________|________|
|                        |    |                         |        |
|Mean Variation          |  V | average of V1 > V5      |     2  |
|________________________|____|_________________________|________|
|                        |    |                         |        |
|Greatest Variation      |Vmax|  Largest of V1 > V5     |     5  |
|________________________|____|_________________________|________|
|                        |    |                         |        |
|Difference V -> H       |  D | Av(M1>M2) - Av(M9>M10)  | -6/+8  |
|________________________|____|_________________________|________|
|                        |    |                         |        |
|Largest Variation       |    |Largest Value difference |        | 
|from mean               |  P | between any individual  |  10    |
|                        |    |M and average of M(1>10) |        |
|________________________|____|_________________________|________|
|                        |    |                         |        |
|Thermal Variation       | C  | (M13 - M11) / (38 - 8)  | +/-0.6 |
|________________________|____|_________________________|________|
|                        |    |                         |        |
|Rate Resumption         | R  | M15 - Ave(M1->M2)       | +/-5   |
|_______________________ |____|_________________________|________|



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