Grand Seiko Quartz
In 1969, Seiko introduced the world's first quartz watch, the Grand Seiko Quartz. Since then, they have led the way in quartz technology and innovation. In 1988, the first Grand Seiko Quartz was introduced, with an exceedingly higher accuracy (nearly 25 times that) compared to conventional quartz watches with a rating of +/- 10 seconds per year. In 1993, Grand Seiko introduced the "Quartz that surpasses quartz" with the 9F Series. This quartz not only maintained the same accuracy at +/- 10 seconds per year, but also featured a backlash auto-adjust mechanism, a twin pulse motor and an instant calendar change mechanism.
Seiko grows and specially selects the finest quartz crystals for Grand Seiko. This process can take up to 6 months. After selected, the crystals are then cut into the shape of a tuning fork. Then, the crystals are aged for 90 days. Each crystal is tested in various temperatures and once the temperatures affects on the crystal are determined, the characteristics are then paired with an IC programmed with that crystals variation. The 9F caliber detects temperature 540 times per day and based on the characteristics of that crystal, then compensates for the variations. This is known as thermo-compensation and is what allows for the impressive +/- 10 second per year accuracy, which is only found in Grand Seiko.
The Grand Seiko 9F Calibers also utilize a twin pulse step motor that delivers greater torque making it possible to drive the longer and heavier steel hands used. The backlash auto-adjust mechanism allows for the second hand to land at the precise position directly over the marker using a hairspring from a mechanical watch to automatically adjust backlash between the gears and prevent vibration when the hand lands at the marker. A "Super Sealed Cabin" protects the heart of the Grand Seiko 9F. The rotor and gear train are tightly sealed which dramatically increases the life of lubrication and prevents dust from entering when opened for battery changes. This provides an internal service life of about 50 years. A pacing switch allows for fine adjustments to be made with opening the sealed cabin. This switch, similar to a mechanical watches adjustment, allows adjustments to be made to improve accuracy if necessary. The Grand Seiko 9F Quartz also features an instantaneous date that amazingly changes in 1/2000th of a second. All Grand Seiko 9F calibers are manufactured and hand assembled in the Shinshu Watch Studio in Shiojiri, in the Nagano prefecture of central Japan. With their immense percision and perfection, the Grand Seiko Quartz are among the finest watches in the world.