Learn more about Calibre 9F
From the pendulum to the quartz crystal
Different as they were in many respects, both the early mechanical clocks from Europe and Japan kept time using a mechanism called the foliot balance, which utilized the moment of inertia. There could be, however, errors of as much as one hour a day. The precision of mechanical timepieces was raised dramatically with Galileo’s discovery of the isochronism of the pendulum. At the beginning of the 17th century, European clockmakers replaced the pendulum with a hairspring and a balance wheel to make their clocks more accurate and compact. Ever since, this system has served horology extremely well and its longevity is clear proof of its excellence. It remained unchallenged as the gold standard method of time regulation until the long, protracted race to the quartz era was won. The quartz clock built in 1927 did not rely on the principle of the pendulum and delivered much greater accuracy, but it was the size of a chest of drawers. It took forty more years for quartz timekeeping to arrive on the wrist. In 1969, the Seiko Quartz Astron arrived.
The path toward recognition as an IEEE Milestone
When AC voltage is applied to a quartz crystal, the crystal vibrates steadily. This principle was applied in the quartz clock, but even in an indoor, static device, there was the issue of its vulnerability to temperature variations. In the 1930s, a Japanese scientist discovered that crystals cut at a specific angle were resilient to temperature change. Seiko developed a quartz clock the size of a locker in 1958, but just eleven years later, the company succeeded in developing a quartz crystal oscillator in the shape of a tuning fork, an integrated circuit with low power consumption, and an open step motor (designed to have the parts of a miniature motor distributed in the spaces of the movement). Thirty-five years after the release of the world’s first quartz wristwatch, it won recognition from the IEEE (Institute of Electrical and Electronics Engineers, Inc., an organization of technical professionals based in the United States) as a milestone achievement and was registered on the List of IEEE Milestones.
What is a regulation switch?
There are several ways to adjust the precision rate of a mechanical watch and the most reliable is the regulator, which makes fine adjustments to the balance spring’s range of motion. The Grand Seiko team recognized its value. Calibre 9F also has a regulation switch with plus to minus graduations marked on it. This mechanism adjusts precision by switching the circuit to make corrections after a designated span of time. Let’s remember that Calibre 9F is, in all but the most extreme conditions, precise to ±10 seconds per year. The regulation switch allows adjustments within this range. If a comparison were to be made, you could say that it is somewhat like the designation of a leap year to adjust the calendar. One gradation in the regulation switch is equal to 0.0165 seconds in a day, or 0.5 seconds a month. Since the movement has a precision that is 100 times greater than that of a highly accurate mechanical movement, the sensitivity of this regulation device is beyond remarkable.