Introduced in 1993 with the marketing claim, "quartz that surpasses quartz", the 9F series boasts precision beyond any other quartz watch. Seiko integrated a number of technical advancements, including a "backlash auto-adjust mechanism", twin-pulse drivetrain, and an instant calendar change mechanism.
Unique features of the 9F quartz calibre:
- A "twin pulse" system gives the movement greater torque, allowing larger and longer hands to be used
- Backlash auto-adjust prevents the hands from vibrating after a power impulse
- The instant calendar change mechanism includes a spring lever mechanism, allowing the 9F calibre to flip the date counter in 1/2,000th second
- The rotor and gear train are sealed in a "cabin", allowing a claimed service interval of 50 years
- Each of the hands moves on its own independent mechanism, allowing all three to move separately and precisely
- Seiko "ages" each quartz crystal for 3 months before timing it to ensure accuracy
- Calibre 9F includes a temperature sensor which adjusts to changes every 160 seconds
- Caliber 9F has a “Pacing Switch” allowing accuracy to be adjusted
The 9F series was refreshed in 2003 along with the release of an anti-magnetic model.
There are four models in the Seiko 9F quartz family:
- 9F61 - Time only
- 9F62 - Date
- 9F82 - Date (updated)
- 9F83 - Day/date
The Seiko 9F calibres are used in the following watches:
- Grand Seiko 9F8 Quartz (1993) - "Quartz that surpasses quartz"
- Grand Seiko SBGX Antimagnetic (2003-present) - 9F61
- Grand Seiko SBGX Quartz (1998?-present) - 9F61/62
- Grand Seiko SBGV Quartz Date (1996?-present) - 9F82
- Grand Seiko SBGT Quartz Day/Date (1994?-present) - 9F83
- Grand Seiko SBGN Quartz GMT (2018-present) - 9F86