What is rate accuracy ?
Is my watch accurate ?
|diameter larger than 20mm||diameter thicker than 20mm|
|Average daily rate||-4 s/j – +6s/j||-5 s/j – +8s/j|
|Mean variation in rates||2 s/j||3,4 s/j|
|Greatest variation in rates||5 s/j||7 s/j|
|Difference between rates in horizontal and vertical positions||-6s/j +8s/j||-8s/j +10s/j|
|Largest variation in rates||10 s/j||15 s/j|
|Thermal variation||+/- 0.6 s/j||+/- 0.7 s/j|
|Rate resumption||+/- 5 s/j||+/- 6 s/j|
In short, the variation in rates of a chronometer must be between -4 s/d and + 6 s/d. Poinçon de Genève (Geneva Hallmark): “ The Poinçon de Genève is a certificate awarded to timepieces with remarkable finishes and decorative details, and provides the connoisseur with proof of the authenticity and horological expertise of Geneva, passed down from generation to generation.” To satisfy the Poinçon de Genève’s standards, a watch must satisfy the following rate accuracy conditions: • Measurements on day 0 and on day 7 are compared with the aid of a vision system that was specially developed for this test. • Days 0 and 7 are compared with a reference time. • After 7 days, the watch must not exceed one minute of variation. In addition, each feature of dial’s indications (day, date, month, etc.) is examined. The variation in rates must be less than 1 minute at the end of these 7 days. The rate accuracy must not therefore surpass +/- 8.6 s/d. Conclusion: – A watch with a variation in rates between -4 s/d and +6 s/d, satisfying one of the COSC criteria, is an example of an excellent movement. –A watch with a variation in rates between -8.6 s/d and +8.6 s/d, satisfying one of the Poinçon de Genève criteria, is a very nice movement. – More generally, a watch with a variation in rates between -10 s/d and +10 s/d is very appropriate. If it goes beyond 10 s/d, it starts to become fairly inaccurate and you should certainly consider having the movement serviced.
What does the frequency indicates ?
What is the amplitude ?
What is a desirable amplitude ?
What is beat error ?
What is the lift angle ?
Countinuous analyse your watch
Countinuous analyse your watch
- The normal curve corresponds to the average accuracy.
- The dotted curve corresponds to the current accuracy (for the last 30 seconds)
If you don’t move the watch, you can observe the current variations of the watch and see how the mechanism varies over time. Depending on how gears teeth engage, the way energy is transmitted to the balance wheel, the movement’s accuracy will be changed slightly. This is why accuracy will vary over time. The chart above is a typical example of this kind of measurement. The normal curve, or the average accuracy, stays constant while the dotted curve, or the current accuracy, rises and falls around the normal curve. On the contrary, if you modify the position of the watch during this measurement or use a function such as the chronograph, the measurement will be much more compelling as you can observe the movement’s “live” reaction. The following chart is a typical example of this kind of measurement: In the example above, it is easy to observe the evolution of the rate when the chronograph is engaged as well as when the watch’s position is changed. Don’t hesitate to do the same with your movements to have a better understanding of how they work.
When launching a measurement my mobile device doesn't detect the frequency
- iOS: Double click on the “Home” button and slide the Watch Analyser application upwards to close it. Then reopen the application.
- Android: Click on the button to make currently open applications appear and slide the Watch Analyser application to the side to close it. Then reopen the application.
2: Watch Analyser is not detecting the signal coming from the watch. This could be due to the fact that the watch is not correctly placed on the electronic sensor. Reposition the watch on the Watch Analyser cushion and make sure that the watch is tightly fastened to the cushion. You can even press the watch against the detector to make sure the sound is correctly transfer to the Watch Analyser.