Quartz watches and mechanical watches - what is the difference?
We will explain by example
Quartz watches that you have come to be familiar with.
These are just like airplanes, controlled by computers.
A battery, IC, and crystal make quartz watches work accurately, electrically.
Some loss or gain may occur while the watch is worn. However, this will be too small to notice in your daily life.
If a quartz watch resembles an airplane, a mechanical watch is like a bicycle.
All watch parts work together mechanically to make it tick.
Thus, a mechanical watch is easily affected by the outside environment.
If it is hot, the watch tends to lose time. When power driving the watch becomes short (when the amount the spring is wound is short), accuracy becomes unstable.
If the resting position of the watch is changed, accuracy is also affected.
The rate of loss/gain could be significant that you will notice in your daily life.
The accuracy is shown by the daily rate
The measured loss/gain of the watch per day.
This is called the daily rate.
The accuracy of a mechanical watch is usually shown in this daily rate.
The accuracy of a mechanical watch changes delicately day by day, depending on the condition in which the watch is used or the outside environment.
Thus, by only observing loss/gain in one day, you cannot judge how accurate the watch works.
If you check the average of the daily loss/gain rates for one week to ten days, you can judge the accuracy of the watch.
In the case of quartz watches, the accuracy is usually shown by the monthly/yearly rate.
Total losses/gains for a month/year are called the loss/gain rate of quartz watches.
Mean daily rate / Normal usage accuracy
The accuracy of a mechanical watch varies depending on many things, such as the amount the spring is wound, temperature, or resting position of the watch.
Thus, to show the accuracy of a mechanical watch evenly, not depending on the environment, loss/gain of a mechanical watch is measured before the movements of the watch are put in the case, under controlled conditions, with many days of tests.
And the measured rate is called “mean daily rate”.
In both the ISO3159 and the Grand Seiko Standard*, the standard rate is mean daily rate.
“THE GRAND SEIKO STANDARD” THE GRAND SEIKO STANDARD
This rate is the data measured in an environment that is artificially controlled, in order to fairly evaluate/show the abilities of mechanical watches without being influenced by environmental changes. So it is different from “normal usage accuracy” when you are actually wearing the watch.
The accuracy of a mechanical watch varies delicately day by day, depending on the environment.
This is like a living thing, one of the charms that a mechanical watch has.
This watch has a precision rate of -1 to +8 seconds a day. If the average of the daily rates exceeds this level, we recommend adjusting the watch accordingly. To adjust the accuracy as accurately as possible, information such as the rate of loss/gain of your watch and how you use it, are very important. Please let us know the following when you ask for adjustment of your watch by our service center.
The average daily loss/gain rates for one week to ten days
Approximate hours of wearing the watch in one day in the above period
The resting position of the watch while you don’t wear it
Ex. an average of +11 seconds
Ex. Approximately 10 hours
Ex. Horizontal - Dial up
Vertical - the crown up