====== Seiko 9F ======
[[Seiko]]'s high-accuracy [[quartz]] movement line is the **9F** series.

===== Overview =====
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.

Earlier [[Grand Seiko]] quartz movements boasted 10 second per year accuracy, including the [[Seiko 8J|8J]], [[Seiko 95|95]] and [[Seiko 3F|3F]] calibres.

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

===== Versions =====
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

===== Applications =====
The Seiko 9F calibres are used in the following watches 

  * [[Grand Seiko 9F8|Grand Seiko 9F8 Quartz]] (1993) - "Quartz that surpasses quartz"
  * [[Grand Seiko SBGX|Grand Seiko SBGX Antimagnetic]] (2003-present) - [[Seiko 9F|9F61]]
  * [[Grand Seiko SBGX|Grand Seiko SBGX Quartz]] (1998?-present) - [[Seiko 9F|9F61/62]]
  * [[Grand Seiko SBGV|Grand Seiko SBGV Quartz Date]] (1996?-present) - [[Seiko 9F|9F82]]
  * [[Grand Seiko SBGT|Grand Seiko SBGT Quartz Day/Date]] (1994?-present) - [[Seiko 9F|9F83]]
  * [[Grand Seiko SBGN|Grand Seiko SBGN Quartz GMT]] (2018-present) - [[Seiko 9F|9F86]]


{{tag>Seiko_calibres Quartz_movements}}