Before shipping, we have tested and calibrated each one.
You may be wondering what we mean by calibration. A mechanical watch relies on a very fine spring and a balance wheel that swings back and forth to control its rate. This mechanism can be adjusted to speed up or slow down the watch. The movements that we are using are made by Miyota in Japan. When they are delivered from the factory, they have not been calibrated and they may be as much as 20 seconds per day slow or 40 seconds per day fast. By calibrating them, we will narrow this range to between -4 seconds and +8 seconds per day.
Because the balance wheel is affected by gravity, the movement will be faster or slower depending on the orientation of the watch. In our calibration, we are therefore taking the average of the rate between a horizontal position and the crown down position. This average should most closely match the orientations of daily use.