What are the meanings of the characteristics of a timepiece?

  English term Synonym
[Derived terms / Abbreviations]		 Definition
Accuracy state   Difference between the displayed time on the timepiece and the standard time.
rate   Measurement value of the clock accuracy over a short period and converted into a daily rate.
daily rate   Difference in two clock states measured at a 24-hour interval.
monthly rate   Difference in two clock states measured at a one-month interval.
annual rate   Difference in two clock states measured at a one-year interval.
drift   Variation over time of the clock rate or daily rate. It is the difference in unit of time between two rate values or daily rate values measured under the same conditions on different days.
regulation   Adjustment of the timepiece accuracy.
theoretical regulation   Method to regulate a timepiece by adjusting the pulse in part of the frequency divider circuit without adjusting the quartz oscillator frequency.
thermal compensation   Compensation for temperature changes that can affect the accuracy of the timepieces and their functions.
operational temperature range   Temperature range in which a (quartz) timepiece can operate.
usage temperature range   Temperature range in which a timepiece can maintain stable performance.
normal usage accuracy   Accuracy of a watch when worn at the wrist at least during 8 hours in a day with a temperature between 5 C and 35 C. Usually a watch is adjusted to have the best accuracy stability in these conditions.
Water resistance
performance		 water resistance   Performance of resistance against ingress of water or sweat inside the timepiece case.
Water resistance means that the timepiece is better protected than devices protected only against water for daily use.
non-water resistant   No resistance to water.
water resistant
for daily use		   Protected against rain and water drops resulting from sweating or face cleaning in everyday life.
The requirements and test methods are defined in JIS B 7021 - Water resistant watches for general use and ISO 2281 - Water-resistant watches.
enhanced water resistant
for daily use		   Protected for immersion in water, such as when swimming.
The requirements and test methods are defined in JIS B 7021 - Water resistant watches for general use and ISO 2281 - Water-resistant watches.
water resistant
for air diving		   Protected against immersion in water up to a depth of 100 m when diving using compressed air as breathing gas.
The requirements and test methods are defined in JIS B 7023 - Divers watches and ISO 6425 - Divers watches.
water resistant for
mixed-gas diving		   Protected against immersion in water up to a depth of 200 m when diving using compressed gas mixture (inert gas such as helium with oxygen) as breathing gas.
The requirements and test methods are defined in JIS B 7023 - Divers watches and ISO 6425 - Divers watches Annex A.
water resistant
for diving		   Generic term of water resistance for both air and saturation diving.
Magnetic resistance
performance		 magnetic resistance

antimagnetism		   Resistance against external magnetic fields.
Type 1 can resist a direct current magnetic field of 4,800 A/m, and type 2 can resist a direct current magnetic field of 16,000 A/m.
The requirements and test methods are defined in JIS B 7024 - Magnetic resistant watches.
magnetic shield   Protection of the movement (and the motor in particular) against external magnetic fields.
Shock resistance
performance		 shock resistance   Resistant against shocks.
Shock-resistant watches can resist a free fall from 1 m height to a horizontal wooden hard surface.
Test methods are defined in JIS B 7001 - Watches and clocks - Test methods, and requirements and test methods in ISO 1413 - Shock-resistant watches.
Miscellaneous practical battery life   Period between the time the prescribed batteries are installed and the timepiece starts functioning and the time it stops or the electric display cannot be read anymore in normal usage conditions.
autonomy   Period during which the timepiece operates with the prescribed performance.

(Note): The above information applies to the members of
the Japan Clock & Watch Association and their products.