The primary correction is an average of about 15-20 data cycles.
The secondary corrections are an average of 8 cycles.
Kriëger Marine Chronometer K6006.1.17 (K89.01/01 = ETA 988.352)
Omega Constellation Perpetual Calendar (Cal.1680 = ETA 252.511)
Longines Conquest V.H.P. Perpetual Calendar (L.546.2 = ETA 252.611)
Citizen Exceed EBJ74-2101 (Cal.E510)
Seiko Superior Twin Quartz (Cal.9983)
Seiko Superior Twin Quartz (Cal.9681)
The final values after all the corrections CAN be slow ...
Sinn vocabulary page is interesting.
Correction interval in quartz movements.
A range of different techniques has been used in different developments to optimize the accuracy of quartz movements. In the past manufacturers tried to produce the quartz as precisely as possible, to grind it or to set the precise oscillation frequency by depositing layers of vaporized gold and then removing it by laser. Today, quartz crystals are ground in such a way to produce a significant gain in the movement. This gain is then measured in each individual movement at room temperature. Subsequently the movement is programmed so that the gain is corrected every one to four minutes (depending on the caliber). The movement is briefly "paused" to compensate for the gain of the quartz oscillation. In quartz chronometer movements there is also temperature compensation. The temperature sensor on the movement plate then helps to determine the current temperature in the watch and to calculate a correction value accordingly. The correction value which is applied once the inhibition cycle is complete is therefore not constant in quartz chronometer movements; rather it is continually adjusted in line with the current movement temperature.
"Forever is composed of nows." - Emily Dickinson
"The watch has to be surrounded by a history.
You need more than just a great design. You need to create an atmosphere around the product.
Who is the company behind it? Why are they using this material?
People need to be able to identify the watch with themselves. It's based on emotion." - Ralph Furter
...that's just my opinion and I've been wrong before and will be again and might be now!
I can see around a 0.031 millisecond gain every second.
That happens to be exactly one tick.
One quartz vibration that takes 1000/32768 milliseconds.
Left uncorrected that would add up to 900 seconds per year.
So I think ETA counts to 32767 when counting for a second. And thus ensuring the clock runs fast.
And that way they don't have to select crystals.
All speculation off course!
The end result remains the same: The clock runs fast, and the corrections slow it down.
Last edited by Hans Moleman; September 8th, 2009 at 03:56.
Why not get closer to 2^15 Hz and decide to add or subtract counts?
If you only subtract when applying corrections you don't need to have signed numbers. A bit cheaper I believe. Or at that time anyway. They were fighting for every bit at that time.
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