Expert: Martin Meyer - 4/17/2008

Question
What does "unadjusted" mean when on a quartz mechanism.  I can't seem to find it in any on-line clock glossaries.  My clock is a Hermle 2114.  Thank you for your time.

Answer
Hi Ed,
    "Adjusted" and "unadjusted" are more watchmaking terms than clock terms. "Adjustments" are complicated processes to make a watch keep time at the same rate in 1)different temperatures, 2) "isochronism", when the watch is fully wound versus nearly unwound, and 3)"positional", when the watch is in different positions, such as face up, face down, etc.
    In clocks, positional error is not, of course, an issue. Isochronism is only an issue for mainspring-driven clocks, as weight driven clocks supply even power at all times. Temperature compensation is an issue for all mechanical clocks, and is remedied (if at all) by bimetal pendulum rods or bimetal balance wheels.
    In quartz clocks, none of these adjustments are really an issue. The battery will supply even power until it is nearly dead. It's beyond my expertise to know if temperature has any noticeable effect on the electronic movement, but I doubt it. I have never seen a quartz movement which is marked "adjusted".
    Historically, watchmakers marked most or all their movements as "unadjusted" because tariff laws provided lower rates for "unadjusted" watches. Ultimately, the distinction came to have virtually no meaning.
    I suspect that the marking on quartz clock movements is either traditional or related to import/export laws, and has no practical meaning.