On the wrist, the watch is subjected to frequent accelerations and numerous impacts of all levels of intensity. These mechanical stresses affect the behaviour of the movement (rate, amplitude), but can also be behind malfunctions (unscrewing or screws breaking, dial or hands shifting, loss of appliques…)
Multiple shock tests involve applying to cased movements, watch cases or any other item of similar size, a series of linear shocks of calibrated acceleration and duration, in one or more directions. The characteristics of the movement (operation, possibly rate, amplitude…), of the casing (movement, dial and hands fastening…) and of the case (assembly, crystal, water resistance…) are inspected before and after testing.
On cased watch movements, the multiple shock program applied generally comprises linear accelerations of between 250 m/s2 and 5500 m/s2. Depending on the requirements, any other program can be applied up to linear accelerations of 10'000m/s2.
Note: 9.81 m/s2 = 1gn