Clock drift
The term clock error is understood to mean the deviation of the time indicated by the clock time from a reference time that is predetermined by a time standard. This deviation may be constant, steadily rising or falling, or variable.
Watch stand
A constant over a longer period deviation is called the Watch stand (also: state failure or state ). Basically, the clock is running correctly, it is only set to a desired " target time " (eg, the Central European Time) different time. The sign of the Uhrstandes is generally specified in terms of a case to be made improvement. If the clock is slow for example 20 seconds, the Watch stand is 20 s You have to add 20 seconds to get the correct time.
Uhrgang
The Uhrgang (also:. Transition or umgangspr accuracy ) refers to a rising or falling deviation of the time displayed in one day. By observing this deviation over a longer period, you can determine the average daily passage of a clock.
The difference in the daily deviations to each other, so the fluctuations in the transition of the clock, referred to here as response errors. A transitional error may be due to a lack of movement, but also be caused by dirt and wear, or due to external influences such as temperature or air pressure changes. When pocket watches can also the location, ie the way of wearing the clock to try to influence the daily course.
For quality checks these external influences are largely eliminated by constant test conditions and testing in different layers. Mechanical watches that have passed a continuity test an official gear control body (eg the COSC) may be marked as a chronometer. Quality feature here is a mostly constant mean daily change, so that a low response errors.
In daily use, you try to compensate for higher value Clocks by offsetting unavoidable external influences. For radio controlled watches the response errors only plays a minor role, since the correct time is regularly adjusted by means of a time signal transmitter.
For a brief response measurement of mechanical watches using a time scale.
Documents
- Timekeeping
- Uhrentechnik