Citizen ChronomasterBy Darren Ho
At Revolution, we’ll be honest in saying that we’re a tad biased towards mechanical watchmaking. In recent days, however, there’s been increasing interest in redefining electronically assisted timekeeping – quartz-powered timekeepers are no longer simply the more accessible option. This redefinition is in no small part due to the presence of smartwatches, which are driving forward digital timekeeping efforts. As a result, high-precision quartz timekeeping is making a strong comeback.
Some quick numbers to note: according to the Contrôle Officiel Suisse des Chronomètres (COSC), mechanical tickers are considered to be highly precise when they maintain a rate of −4/+6 seconds per day. While the typical quartz timepiece maintains a ±1 second a day average and good quartz timepieces make ±15 seconds a month, by COSC standards, a quartz chronometer holds a requirement of ±25.55 seconds a year. Why are we referencing all these numbers? Because Citizen’s Chronomaster timepieces are accurate to ±5 seconds a year. That’s over five times more precise than international standards require.
It’s easy to brush aside quartz timekeepers as being digital machines, but it’s not quite as simple as that. Quartz oscillators have to be carefully tuned and designed so that the crystal vibrates at exactly 32,768Hz (a factor of two that can then be digitally divided to a single count a second). It’s also how some rare quartz timepieces have seemingly sweeping seconds hands — instead of counting down to a single count a second, they do two, four or eight, and thus the hand moves incrementally. Conversely, the rare mechanical complication that is the deadbeat seconds is an everyday appearance on a quartz watch.
Akin to a hairspring’s isochronism, the element that most easily affects a quartz watch’s precision is temperature change. As the vibration of the crystal speeds up or slows down slightly at different temperatures, it can affect the accuracy of the timekeeping.
Accuracy performances aside, it’s what else is present within the Chronomaster AQ 4020-54Y that lights this watch up. To highlight its Japanese origins, Citizen has used washi paper on its dial. Washi paper, a hand-processed traditional Japanese paper-making craft, is produced using the inner bark from three types of Japanese flora and is recognised as a UNESCO cultural heritage. It’s still found today in various Japanese traditions and is used internationally in book mending and conservation. It’s a hardier paper fibre and Citizen has found a way to treat it and use it as a dial.
Naturally it’s not so strong that it can hold the indexes and cannon pinion. These are mounted on a transparent dial above the washi paper, that also acts as a solar cell to charge the capacitor in the movement. Thanks to Citizen’s proprietary Eco-Drive solution, the watch never needs battery replacements – keeping it exposed to the sun for 30 minutes or so each day should suffice.
The case of the Chronomaster AQ 4020-54Y is equally surprising. Citizen uses a hardened titanium case, one that is developed internally. Known as Super Titanium and hardened using a technology called Duratect, it offers up a significantly harder case surface than typical titanium. The process, a vacuum furnace heating with a proprietary gas mixture, can offer up to nearly 10 times the standard hardness of pure titanium. The Super Titanium found on the AQ 4020-54Y is four to five times harder than your standard offering, meaning it’s less likely to suffer scratches and dents. This watch is the literal incarnation of Daft Punk’s “Harder, Better, Faster, Stronger”. Literally.
Quartz Eco-Drive A060; hours, minutes and seconds; perpetual calendar; up to 1.5-year power reserve
39mm; Super Titanium; water‑resistant to 100m
Super Titanium bracelet