hen we met Toshihiko Sato, President and CEO of Citizen Group, last April in Tokyo, the Caliber 0100 was quite naturally at the centre of the discussion. With its worldrecord accuracy of ±1 second per year, it represents a milestone for the Japanese brand.

“The Caliber 0100 showcases the high technology that Citizen can bring to the world,” sums up Toshihiko Sato. “We started this project several years ago, finally introducing it this year. The Caliber 0100 is a direct continuation of the history of Eco-Drive, which has been around for more than 40 years.”

Despite the current worldwide focus on mechanical watches, and the simultaneous rise of smartwatches, Citizen has never abandoned its research into the accuracy of quartz timepieces, always using the power of light with Eco-Drive technology.

As a reminder, the aim of this technology is to make up for the shortfalls of quartz watches, namely the relatively short battery life, the inconvenient process of replacing batteries and the environmental issues of battery disposal.

“The Caliber 0100 is a direct continuation of the history of Eco-Drive, which has been around for more than 40 years.”

White Gold model (AQ6010-06A)

The beauty of simplicity is reflected in this limited edition with ultra-precision accuracy of ±1 second per year. The case and crown are crafted out of lustrous white gold, with a crystal design motif suggesting ultra-precision and the crystallisation of Citizen technologies, as well as the “purity” of the individual seconds. The Caliber 0100, housed inside the white gold case, is made of a black discolouration- and corrosion-resistant rutheniumplated material, with a unique striped finish visible on the back of the watch through the sapphire glass. The tip of the second hand and the edge of the ivory dial create corresponding arcs, enhancing the movement of the second hand, which aligns perfectly with the indices. The strap is textured black crocodile with subtle toneon- tone stitching. An individual serial number is etched on the back, indicating the limited number of 100 units available for the worldwide market.

Heir to the Crystron Mega of the 1970s

Back in 1975, the Crystron Mega succeeded in achieving record-breaking precision of ±3 seconds, as we documented at the time in Europa Star. So how did Citizen’s R&D teams achieve this new precision of ±1 second, without relying on data from radio towers or satellites?

As the brand explains, the first step was to replace the traditional tuning fork-shaped crystal oscillators generally used in quartz watches with AT cut type crystal oscillators. These oscillators vibrate at a frequency of 8.4 MHz (8,388,608 Hz), which is more than 250 times higher than tuning fork-shaped crystal oscillators. It ensures that this new mechanism remains resistant to outside influences such as temperature fluctuations and the effects of gravity, as well as age degradation.

AT cut type crystal oscillators, however, require greater amounts of energy to operate. The brand explains that it was able to compensate for this by thoroughly vetting the materials used, utilising intelligent design, and refining control over its power-saving strategies.

As a result, Caliber 0100 technology allows the Eco- Drive to run continuously and with significantly greater stability for up to six months on a single full charge (8 months on power save mode), even without the presence of a light source.

The Caliber 0100 utilises AT cut type crystal oscillators that vibrate at a frequency of 8.4 MHz (8,388,608 Hz).

Up to six months on a single full charge (8 months on power save mode), even without the presence of a light source.

What’s more, the Caliber 0100 maintains its greater accuracy by continuously monitoring and adjusting for frequency and temperature shifts once every minute. The optimal running temperature is between 5°C and 40°C, which is considered the most practical watch temperature environment for most regions of the world.

A new circuit design also incorporates higher shock resistance, which automatically corrects the position of the watch hands, and an antimagnetic feature to protect the movement from the effects of magnetic forces. All these innovations combine to deliver an unprecedented ±1 second per year precision accuracy.

According to Citizen, the individual hand movements of the Caliber 0100 are the physical expression of “a second in its purest form”.

A design stripped down to the essentials

Beyond this technological innovation, it is very interesting – and revealing of the current transformations in Japanese watchmaking, which is tending more towards emotion and luxury – to note that the Caliber 0100 is housed in a very sober yet elegant case. At first sight, the external appearance of the watch gives no clue to the presence of the worldfirst technology inside.

In accordance with the simplicity of each second, the design of the timepiece has been made pure and timeless. Or, as the brand puts it perfectly: “The Caliber 0100 expresses the beauty of individual seconds in their purest form: superfluous adornments have been minimised to produce the ultimate simplicity.”

One of the most important characteristics of the dial is the fact that the second hand aligns perfectly with the indices when viewed from the front. The individual hand movements are the physical expression of “a second in its purest form,” achieved by adopting the LIGA fabrication process (a manufacturing technology for making high-aspect-ratio microstructures) for individual components.

Ordinarily, gears and springs are machine cut and pressed. With LIGA fabrication, more intricate components can be manufactured. Special components made by combining customised springs and gears produced by LIGA manufacturing prevent even the tiniest inconsistencies in the gears from affecting hand movements, thus ensuring that the hands align perfectly with the indices.

In accordance with the simplicity of each second, the design of the timepiece has been made pure and timeless.

Long, heavy brass elements, which ordinarily cannot be propelled by the traditional torque motors of quartz movements, are used for the watch hands. The simple aesthetics of the exquisite brass hands featured in these new models reflect the design concept of “conveying the purity of every second with superb accuracy”.

Citizen’s own skilled watchmaking “meisters” are responsible for assembling the Caliber 0100. These master craftsmen and women supervise the process and ensure the highest quality and accuracy. It’s also their responsibility to ensure precision alignment of the second hand with each of the 60 indices, once it is fitted.

Super Titanium Models (AQ6021-51E / AQ6020-53X)

The AQ6021-51E comes with a rich and lustrous metallic black dial. The dial material absorbs light through an array of tiny apertures on the front, suggesting the relationship between light and time. The AQ6020-53X comes with a mother-of-pearl dial, evoking the never-ending passage of time in the natural world. The contrast between the sophisticated mother-of-pearl pattern, formed over many years, and the second hand that marks each precise second, makes this watch uniquely striking. The presence of moments in the passage of eternal time — highlighted by the ultra-precise accuracy of ±1 second per year — is symbolised by the design itself. Both models feature the “crystal” motif on the case, crown and bracelet. The evocative cuts at various angles provide a variety of expressions depending on the angle of light. Designed for longevity, these models are constructed from Super TitaniumTM with Duratect α. A serial number on the back of the case indicates the limited number of units available worldwide.

The price of the watch is $7,400 for the titanium version (limited to 200 pieces with mother-of-pearl dial and 500 pieces with black dial), and $16,800 for the white gold version (limited to 100 pieces).

CITIZEN’S WORLD FIRSTS

• 1967 - World’s first electronic quartz clock, "Crystron
• 1972 -World’s first electronic watch with time signal time setting
• 1975 - World’s first accurate quartz watch, "Crystron Mega
• 1976 - World’s first LCD quartz watch with alarm
• 1976 - World’s first analogue quartz watch using light as power source “Crystron Solar cell”
• 1978 - World’s first watch with movement under the onemillimetre barrier
• 1980 - World’s smallest ladies’ analogue quartz watch
• 1982 - World’s first dive watch with 1300m pressure resistance, “Professional Diver 1300M”
• 1985 - World’s first dive watch with an electronic depth meter, "Aqualand
• 1987 - World’s first voice recognition watch
• 1987 - World’s first light powered combination watch
• 1988 - World’s first digital watch with shock switch "Shock Sensor
• 1989 - World’s first professional climbing watch with electronic elevation sensor, “Altichron”
• 1989 - World’s first analogue quartz watch with a perpetual calendar
• 1992 - World’s first dive watch with analogue depth meter, “Analog Depth Meter”
• 1993 - World’s first multi-band (Japan, Germany and Britain) radiocontrolled watch
• 1994 - World’s first professional dive watch with a depth sensor and a data transfer system, “Hyper Aqualand”
• 1997 - World’s first light powered watch with accuracy of ±10 seconds per year
• 1997 - World’s first analogue quartz grand complication watch
• 1998 - World’s first light powered analogue depth meter dive watch
• 2002 - World’s smallest movement watch
• 2006 - World’s first Bluetooth connected watch
• 2011 - World’s first satellitesynchronised watch
• 2016 - World’s thinnest light-powered watch
• 2017 - World’s first light-powered saturation diving watch water-resistant to 1000 metres
• 2019 - World’s most accurate lightpowered watch

The new Caliber 0100 is heir to the ultra-precise Crystron Mega of 1975. These pages from the Europa Star archives provide some information about this pioneering timepiece, which achieved an accuracy of ±3 seconds.

Europa Star 2/1976 - Europa Star 4/1976 - Europa Star 5/1977 - Europa Star 1/1977