The watch factory tell you about how much the standard error

Since winding mechanical structural characteristics, materials, friction and fatigue, the output torque between the ring changes from strong to weak, and the like clockwork and friction gear torque generated during transportation, it will affect the accuracy of travel time clocks. Further climate temperature, gravity, magnetic field, the local environment and location, etc. also affect the normal operation of the spring pendulum clock. Now quartz watches, mechanical watches to overcome weaknesses, take advantage of extremely stable frequency vibration of a quartz crystal as a reference time. Quartz watch time go error typically ± 0.5s (superior products), mechanical watches time go range error ± 15s/d-- ± 120s/d