Comments:
UFA Spring Drive: New on the Block.
Exciting discovery: absolutely fascinating movement with sensational accuracy. Beautiful in 37mm with a misthic dial from the Japanese culture.
Congrats!
It’s a great size at 37mm instead of all these 40-42s, much more classical looking. If you can, please let us know in a couple months the real accuracy of the movement. The Japanese generally downplay a lot the actual precision of their movements, for example the SLGA021 can be +-10s a month but mine is actually +1s a month. I really wonder how these UFA fare in real life.
The movement in your SLGA021 has all the same tech as the UFAs
They even have a spot for a regulator switch, which is unused and hidden below the plates.
Oh I didn’t know that there was a spot for the regulator.
So I wonder why the difference for stated accuracy intervals, for the caliber 9RA2 it’s +-10s a month but for the UFA it’s +-20s a year. I thought maybe they were using a better quartz crystal or something.
The UFA does use selected crystals that have been aged and confirmed as most accurate in a batch
Here’s the watch’s special page LINK TO GS PAGE
From the press release:
The new movement achieves its ±20-seconds-per-year accuracy thanks to new and enhanced manufacturing and processing methods for the three-month-aged quartz oscillator, and a newly designed IC.
As with the 9RA series of Spring Drive movements, the frequency of each individual quartz oscillator is measured at several different temperatures, with the resulting data necessary for thermo-compensation programmed into the low-power IC. Both the oscillator and sensor are vacuum-sealed to minimize temperature differences and protect against external factors such as humidity, static electricity, and light, ensuring precise temperature adjustments and the stable performance of the quartz oscillator.
The pursuit of high accuracy has always been the cornerstone of Grand Seiko’s values. Receiving the new U.F.A. designation, which stands for “Ultra Fine Accuracy,” Caliber 9RB2 boasts a level of precision defined not by accuracy in seconds per day, week, or month, but by accuracy over one year. The movement has an astounding annual rate of ±20 seconds, or approximately ±3 seconds per month.
So they produce better quartz +
the IC is better. Wonder when they will achieve to have an IC that can work with an AT cut quartz in a spring drive, that would probably be the ultimate accuracy. Thank you sir!
Seiko Epson goes by JIS standard no. B7025 for rating accuracy, which requires a few years of crystal aging date that didn't exist when the 9RA movements were launched
Seiko Epson released a technical paper on the 9RA movements years ago, they knew the 9RA movements could perform to +/-10 seconds a year when new.
You can access a PDF of the paper from this site, but it is in japanse.
www.jstage.jst.go.jp
You can access a PDF of the paper from this site, but it is in japanse.
www.jstage.jst.go.jp
I didn’t know that hot weather made
the quartz slower and cold faster, thanks. Also I thought that they were aging the cristals for 3 months and not for years. Wonder how the 9RA movements will preform after a decade.
This spot here is where the regulator would go
The little cutout and pin sticking through the perimeter plate are for it. There are also contacts for it are on the PCB, but afaik none of the 9RA movements have the switches installed.
It should be almost impossible to measure the accuracy of this watch
You will have to wear it all the time, for months, to see variations, and what reference signal can you compare it to?
Bravo for getting one, and cheers to GS for going all out on accuracy.
I don’t change my high-accuracy quartz watch for daylight savings. It’s now jumping 2 seconds, meaning the battery needs to be changed again … and the variation in time is within those 2 seconds since I last changed it.
My legal-time, 8-satellite receiver ESE-185A GPS Master clock {within 45 nanoseconds of UTC} has a red external display and yellow internal display which show the GS is right on the 12 after a couple years.
We have basically reached the stage where there’s no more fun in measuring variation, yet I still want that VFA watch!
Cazalea
This is also 37mm, and yes, there are tiny lions where the lines intersect!
Beautiful dial with lions!
I did exactly the thing you proposed sir, I wore my SLGA021 daily at home for months. When I was going out I sometimes changed to other pieces but at home committed to it, the 5 days power reserve helped too when for a day or two I wore other watches. It is impossible though to measure the exact accuracy of this watch because the caliber makes no sound, so I just used the watch on my phone as a reference and coordinated my watch as best as I could with the phones watch, after a month it was roughly +1s.
Truly sublime 👏🏻🙌🏻👌🏻
Love everything about it, and the size is spot on 👍🏻 Great shots, too 😊🙌🏻