Grand Seiko Evolution 9 Collection Tentagraph

Last year, at Watches and Wonders Geneva, Grand Seiko introduced its first mechanical compli- cation and a series of sports watches from the Evolution 9 Collection. Today marks a new milestone as Grand Seiko expands its Evolution 9 sports watch offering with its first mechanical chronograph, the Tentagraph.

Just like every Grand Seiko creation, the pursuit of precision is at the heart of the new Tenta- graph, whose chronograph movement features the revolutionary high-beat Caliber 9SA5 as its base. Like Caliber 9SA5, the new Tentagraph Caliber 9SC5 beats ten times per second, ensuring high accuracy when measuring elapsed time as well as the time of day. And, thanks to its energy- efficient escapement and two barrels, the watch runs for three days even when the chronograph is in operation, making the Tentagraph the 10-beat chronograph with the longest power reserve in the industry today.* Furthermore, the Tentagraph is subjected to a new and longer testing procedure. As with all Grand Seiko mechanical movements, the Tentagraph’s time-of-day accuracy is assessed in six positions and at three temperatures over 17 days but, in addition, there are three more days of testing during which the accuracy is assessed in three positions while the chronograph is in operation. Thus, in total, each Tentagraph movement is tested for 20 days to ensure that it meets the Grand Seiko Standard of +5 to -3 seconds per day.