Overview Mechanical watch movement which has a balance wheel consisting of balance and hairspring, the stability of its oscillation cycle determines the timing accuracy of the watch. The balance of the balance wheel swings left and right, and the amplitude of its swing is the swing. The swing is also called the amplitude in the watch industry. According to the definition of physics, the amplitude is the maximum displacement of the oscillating object from the resting equilibrium position. The swing of the watch is always changing, and its stability and size depend on many factors. The most important thing is determined by the tightness of the clockwork, clockwork is more full, then the higher the swing. In addition, and the balance of the axis of the balance wheel is also relevant, when the position changes, the balance spring balance wheel balance and shaft tenon friction status also changes. For example, when the watch is in the plane and the vertical plane, the change of the swing is very obvious, the elevation is usually about 40 degrees lower than the plane swing. Other factors that affect the swing are many, such as: watch design issues, lubrication conditions, gear axial and radial clearance, winding torque output stability and so on. The watch's swing is not as high as possible, because the maximum rotation of the balance wheel can not reach 340 degrees. If the swing is too high, it will cause the watch to "hit pendulum", which is actually a balance wheel pin striking the outer side of the fork pallet fork a phenomenon that will make the watch time-varying fast, it sounds the watch walking The sound loses its normal rhythm and becomes like an urgent "hooves". Generally believed that the watch in the state of full strings, the swing between 240 ~ 320 degrees more appropriate. measuring Swing drop: the watch in full string and real 24 hours after the two states were measured, respectively, two planes (surface and under the surface) and three vertical surface (the next, the left and the top), which Five changes in the position of the swing, compared with the same position, take the biggest difference as swing gap. Swing drop is also an important indicator of isochronous performance, but also reflects the quality of the clockwork and hairsprings and their design and assembly, usually require a drop of 50 degrees below. Swing up and down difference: watches in full string state, respectively, measured two planes (surface and under the surface) and three vertical surface (the next, the left and the top), the five positions of the swing Change, with a watch on the surface of the plane position and a few vertical position compared to take the largest difference as the swing flat difference. Swing is also an important indicator of the error performance of the position of the watch, usually requiring a difference of less than 50 degrees. 24-hour facade Minimum Swing: The watch in the real 24 hours after the vertical plane (generally choose the left position) the minimum swing can not be less than 180 degrees. In the case of high swing, the watch performs better than when the swing is low, especially for the watch with calendar attachment. The minimum swing of 24-hour facade is especially important. The measurement of the swinging of the watch is generally measured by an amplitude meter. Models such as AM201 and GD-50 were produced in Switzerland in the early years. It is the use of the so-called "base angle method" to measure, so before measuring must choose the corresponding watch measured the rise of the balance. In the use of instrument detection watch, a complete test unit requires a calibrator and amplitude meter. Previous watch repair, I saw with a school meter, watch factory can only see the amplitude meter. Explain that we generally only pay attention to the accuracy of the watch's speed, while the swing and accuracy are equally important and interrelated, the swing of the technical indicators is not good, the gap between the watch over the difference between peace and justice, must also go bad. Especially in the balance balance calibration, adjust the position error, we must refer to the swing, swing concept requires the maintenance staff of the watch a higher level of theory.