Just like every Grand Seiko creation, the pursuit of precision is at the heart of the new Tentagraph, 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.