Normal usage accuracy of a mechanical watch varies depending on individual customer’s use conditions such as winding state of the mainspring by movement amount of the customer’s arm per day, temperature environment, and position (orientation of a watch). Accordingly, the actual normal usage accuracy when the watch is used by a customer may differ from the numerical value of each item specified in the Grand Seiko Standard.
The target range of normal usage accuracy when the watch is actually used by a customer is set to -1 to +8 seconds per day.
To correctly judge the normal usage accuracy, please use the watch for not only one day, but also approximately one week to 10 days under normal use conditions to check loss or gain of time. If the average value per day exceeds the target range, we recommend adjusting the watch. (For more details, please refer to THE GRAND SEIKO STANDARD.)
The enclosed Grand Seiko Standard Inspection Certificate certifies the values of a movement single unit before assembly in a case which are measured under an artificially controlled environment in the production factory passed the Grand Seiko Standard Inspection.
Should the certificate be lost or after repair or adjustment, it cannot be reissued.