A movement , in watchmaking , is the set of parts making it possible to operate a watch . Each type of movement finds its nomenclature under the name of ” caliber” , for example the ” Valjoux 7750 “.
The dimensions of a movement are measured in millimeters, but the watchmakers also use ” the Line “, former measurement equivalent to 2.255 millimeters and designated by the symbol “”.
On average, a simple mechanical movement has 130 pieces [ ref. Desired] .
Hand-wound mechanical movement
A movement consists of the mechanical elements giving the unit of time. The exhaust regulates the energy stored in the cylinder or in the rise of the weight. The barrel contains a spring , manually lifted by means of the winding stem , and which stores the mechanical energy of the movement.
Self-winding mechanical movement
The self-winding movement has the same function as the mechanical movement with manual winding , but the barrel spring is reassembled by an oscillating mass equipped with a double reverse clutch to communicate the force to the barrel.
Electronic movement whose time base is ensured by an oscillating quartz . The energy is supplied by an electric battery . The natural frequency of the quartz is then the time reference. A quartz movement derives from the order of 0.1 ppm (parts per million, or 0.3 s / month), where the drift of a mechanical movement varies between 10 s / d and 6 s / month.