The accuracy of the mechanical watch movement at rest

To establish a benchmark accuracy of a mechanical watch which does not depend on usage environment, loss / gain of a mechanical watch is measured before the movement is assembled in the case. The accuracy of the movement is measured under controlled conditions over a certain number of days, and the result is called "the accuracy of a mechanical watch movement at rest."

 

The measurement result for each watch is written in the "Grand Seiko Standard Inspection Certificate," which is provided with the watch by the retailer at time of purchase. This result is an average loss / gain of time over a 17 day period, which was measured in the factory where the temperature and position of the movement are controlled in accordance with the "Grand Seiko Standard."