The VideoBalisometer is a state-of-the-art equipment intended mainly for watchmaking laboratories, so that they can make sharp measurements on the regulating organ and analyze the influences of all types of exhaust. It can also have the purpose of verifying the measurements made with other types of equipment.
The VideoBalisometer was developed with the aim of replacing the reference system designed by the LSRH [01] in the 1970s (microbalisometer), as well as other devices developed at that time, which today are no longer available on the market. market. It aims to become the repository for measuring amplitudes, steps and speeds of the balance wheel.
It must meet the most demanding needs in terms of watch research and thus offers several major innovations.
Vision measurements are based on the idea of dynamically measuring the elongation of the balance as a function of time. Three aspects are important to guarantee the requested specifications
Achieving the above objectives involves two successive measurement modes: the first must allow viewing of the entire balance (Ø 12 mm maximum) with a limited image acquisition speed. The second should allow the acquisition of a smaller field of vision but at a high rate. It is important to note that, for the system to be able to acquire and plot an elongation curve, the partial field of vision must allow permanent monitoring of the landmarks. In the case of the AP 3120 caliber, the weights are used as a benchmark. The selected vision system allows acquisition of images with a frequency linked to the vertical resolution of the image. To measure the walking and amplitude characteristics, it is not necessary to process all the images of the alternation. Eight acquisition windows for two oscillations (see figure below) are defined and positioned in anticipation of the position of the pendulum
Since without an exhaust there is no acoustic signal, the amplitude, walking and speed measurements are made only by vision.
The operation is slightly different from the measurement in maintained mode, the detection of zero speed images is identical but the method of calculating the amplitude is different. The images corresponding to the turning points of the balance (moment when the balance stops and starts again in the other direction) and the images corresponding to the moments when the speed is maximum are recorded and once the balance is stationary the VideoBalisometer analyzes the recorded images in order to plot the damping curve, the walking curve and the max speed curve.
More technical information is available in the act of the chronometry congress
A motorized system (see Figure 13) allows the assembly to be moved automatically to carry out all the desired measurements, in the following positions
the measurements are carried out without operator intervention, both for the maintained mode and for the free mode.
The VideoBalisometer is state-of-the-art equipment intended mainly for watchmaking laboratories, so that they can carry out precise measurements on the regulating organ and analyze the influences of all types of exhaust. It can also be used to verify the measurements made with other types of equipment.
Developments are planned such as
Audemars Piguet and qmt presented the VideoBalisometer. The documents are available below