Twin Quartz

As history shows the fanatics at Seiko always seek room for improvement, the Seiko 1978 JDM catalogue for instance debuted the now renowned twin quartz caliber - symbolized by the double honeycomb, proudly showing this embossed on the crown and applied on the dial. And if that was not enough, there were (eventually) at least three different design technologies behind these models.

The rationale was that while quartz based watches are extremely accurate compared to mechanical watches, they are still not perfect, one of the main reasons for the inaccuracy in a quartz model is that temperature fluctuations change the oscillation of the quartz crystal to vary ever so slightly. This change in oscillation will cause the slight drift in timing. To compensate for these changes quartz watches will employ some kind of temperature compensation.  

In all five different superior and non-superior calibre series were introduced in less than two and a half years. The Superior 9980 and -83 series, first released in August 1978, the 92 Grand and King Quartz series released in December 1978, closely followed by the 97 King Quartz series released in October 1979 (9722A, 9723A).

Just under a year later the 96 Superior and Quartz series were released in September 1980 as caliber 9641A and 9642, the latter in the inconspicuous Seiko Quartz - a true wolf in sheep’s clothes. Hot on its heels was the 94 Superior (9481/83), but also the Grand, King and Quartz series were released in November of 1980 (respectively 9461, 9443 and 9441). And yes, there was also the maverick Lassale 9442.