Vibrations per hour (vph, VPH) is a mechanical timepiece specification. It is used to express the frequency of a watch movement. [1] [2] VPH describes the number of times that a vibrating timekeeping component completes a vibration cycle in 1 hour. [3] More vibrations per hour yields higher timekeeping resolution, and usually indicates a higher precision mechanical movement. [4]
A clock or a timepiece is a device used to measure and indicate time. The clock is one of the oldest human inventions, meeting the need to measure intervals of time shorter than the natural units: the day, the lunar month, year and galactic year. Devices operating on several physical processes have been used over the millennia.
A pendulum clock is a clock that uses a pendulum, a swinging weight, as its timekeeping element. The advantage of a pendulum for timekeeping is that it is a harmonic oscillator: It swings back and forth in a precise time interval dependent on its length, and resists swinging at other rates. From its invention in 1656 by Christiaan Huygens, inspired by Galileo Galilei, until the 1930s, the pendulum clock was the world's most precise timekeeper, accounting for its widespread use. Throughout the 18th and 19th centuries, pendulum clocks in homes, factories, offices, and railroad stations served as primary time standards for scheduling daily life, work shifts, and public transportation. Their greater accuracy allowed for the faster pace of life which was necessary for the Industrial Revolution. The home pendulum clock was replaced by less-expensive, synchronous, electric clocks in the 1930s and '40s. Pendulum clocks are now kept mostly for their decorative and antique value.
The second is the base unit of time in the International System of Units (SI), commonly understood and historically defined as 1⁄86400 of a day – this factor derived from the division of the day first into 24 hours, then to 60 minutes and finally to 60 seconds each. Analog clocks and watches often have sixty tick marks on their faces, representing seconds, and a "second hand" to mark the passage of time in seconds. Digital clocks and watches often have a two-digit seconds counter. The second is also part of several other units of measurement like meters per second for speed, meters per second per second for acceleration, and cycles per second for frequency.
A watch is a portable timepiece intended to be carried or worn by a person. It is designed to keep a consistent movement despite the motions caused by the person's activities. A wristwatch is designed to be worn around the wrist, attached by a watch strap or other type of bracelet, including metal bands, leather straps or any other kind of bracelet. A pocket watch is designed for a person to carry in a pocket, often attached to a chain.
Seiko Holdings Corporation, commonly known as Seiko, is a Japanese maker of watches, clocks, electronic devices, semiconductors, jewelries, and optical products. Founded in 1881, it is known for introducing one of the world's first quartz wrist watches as well as the world's first quartz watch with a chronograph complication.
In horology, a movement, also known as a caliber, is the mechanism of a watch or timepiece, as opposed to the case, which encloses and protects the movement, and the face, which displays the time. The term originated with mechanical timepieces, whose clockwork movements are made of many moving parts. The movement of a digital watch is more commonly known as a module.
The Contrôle officiel suisse des Chronomètres (COSC), the Official Swiss Chronometer Testing Institute, is the institute responsible for certifying the accuracy and precision of Swiss watches.
Eco-Drive is a model range of watches manufactured and marketed worldwide by Citizen Watch Co., Ltd., powered primarily by light. As of 2007, the company estimated the drive system had eliminated the disposal of ten million batteries in North America.
Zenith SA is a Swiss luxury watchmaker. The company was started in 1865 by Georges Favre-Jacot at the age of 22, in Le Locle in the canton of Neuchâtel. Zenith was purchased by LVMH in November 1999, becoming one of several brands in its watch and jewellery division which includes TAG Heuer and Hublot. Julien Tornare is the current CEO after Jean-Claude Biver in 2017, replacing CEO Aldo Magada, who had replaced Jean-Frédéric Dufour in 2014. Zenith is one of the Swiss watch manufacturers that still produce their own movements themselves.
A balance wheel, or balance, is the timekeeping device used in mechanical watches and small clocks, analogous to the pendulum in a pendulum clock. It is a weighted wheel that rotates back and forth, being returned toward its center position by a spiral torsion spring, known as the balance spring or hairspring. It is driven by the escapement, which transforms the rotating motion of the watch gear train into impulses delivered to the balance wheel. Each swing of the wheel allows the gear train to advance a set amount, moving the hands forward. The balance wheel and hairspring together form a harmonic oscillator, which due to resonance oscillates preferentially at a certain rate, its resonant frequency or "beat", and resists oscillating at other rates. The combination of the mass of the balance wheel and the elasticity of the spring keep the time between each oscillation or "tick" very constant, accounting for its nearly universal use as the timekeeper in mechanical watches to the present. From its invention in the 14th century until tuning fork and quartz movements became available in the 1960s, virtually every portable timekeeping device used some form of balance wheel.
In horology, a complication is any feature of a mechanical timepiece beyond the display of hours, minutes and seconds. A timepiece indicating only hours, minutes and seconds is known as a simple movement. Common complications include date or day-of-the-week indicators, alarms, chronographs (stopwatches), and automatic winding mechanisms. Complications may be found in any mechanical clock, but they are most notable in mechanical watches where the small size makes them difficult to design and assemble. A typical date-display chronograph may have up to 250 parts, while a particularly complex watch may have a thousand or more parts. Watches with several complications are referred to as grandes complications.
Citizen Watch Co., Ltd. is an electronics company primarily known for its watches and is the core company of a Japanese global corporate group based in Nishitokyo, Tokyo, Japan. In addition to Citizen brand watches, it is the parent of American watch company Bulova, and is also known for manufacturing small electronics such as calculators.
The history of watches began in 16th-century Europe, where watches evolved from portable spring-driven clocks, which first appeared in the 15th century.
The Casio F-91W is a digital watch manufactured by Japanese electronics company Casio. Introduced in 1989 as a successor of the F-87W; it is popular for its low price and long battery life. As of 2011, annual production of the watch is 3 million unit.
The Rolex Cosmograph Daytona is a mechanical chronograph wristwatch designed to meet the needs of racing drivers by measuring elapsed time and calculating average speed. Its name refers to Daytona, Florida, where racing flourished in the early 20th century. It has been manufactured by Rolex since 1963 in three distinct generations ; the second series was introduced in 1988, and the third in 2000. While cosmetically similar, the second series introduced a self-winding movement, and the third series brought manufacture of the movement in-house to Rolex.
A mechanical watch is a watch that uses a clockwork mechanism to measure the passage of time, as opposed to quartz watches which function electronically via a small battery, or radio watches, which are quartz watches synchronized to an atomic clock via radio waves. A mechanical watch is driven by a mainspring which must be wound either periodically by hand or via a self-winding mechanism. Its force is transmitted through a series of gears to power the balance wheel, a weighted wheel which oscillates back and forth at a constant rate. A device called an escapement releases the watch's wheels to move forward a small amount with each swing of the balance wheel, moving the watch's hands forward at a constant rate. The escapement is what makes the 'ticking' sound which is heard in an operating mechanical watch. Mechanical watches evolved in Europe in the 17th century from spring powered clocks, which appeared in the 15th century.
The quartz crisis was the upheaval in the watchmaking industry caused by the advent of quartz watches in the 1970s and early 1980s, that largely replaced mechanical watches around the world. It caused a significant decline of the Swiss watchmaking industry, which chose to remain focused on traditional mechanical watches, while the majority of the world's watch production shifted to Asian companies such as Seiko, Citizen, and Casio in Japan, which embraced the new electronic technology.
The history of timekeeping devices dates back to when ancient civilizations first observed astronomical bodies as they moved across the sky. Devices and methods for keeping time have since then improved through a long series of new inventions and ideas. Sundials and water clocks originated from ancient Egypt, and were later used by the Babylonians, the Greeks and the Chinese; medieval Islamic water clocks were unrivalled in their sophistication until the mid-14th century. Incense clocks, which may have been invented in India, were being used in China by the 6th century. The hourglass, one of the few reliable methods of measuring time at sea, was a European invention and does not seem to have been used in China before the mid-16th century.
Quartz clocks and quartz watches are timepieces that use an electronic oscillator regulated by a quartz crystal to keep time. This crystal oscillator creates a signal with very precise frequency, so that quartz clocks and watches are at least an order of magnitude more accurate than mechanical clocks. Generally, some form of digital logic counts the cycles of this signal and provides a numerical time display, usually in units of hours, minutes, and seconds.
The Bozeman Watch Company of Bozeman, Montana, was an American company that designed and engineered its own timepieces and had its mechanical components certified by the Contrôle officiel suisse des Chronomètres (COSC) certified timepieces. The company went out of business in 2015.