Quartz watches are watches that are powered by a battery and does not require manual winding. Quartz watches got its name from the quartz crystal in the watch. How quartz watches work in a nut shell: a small battery in the watch causes the quartz crystal to vibrate; a small computer chip then translates these vibrations into pulses that drive a stepping motor that causes the gears that move the watch's hands to turn. Quartz watches were introduced in the late 1960s and really flourished in the 1970s due to its significant lower cost as compared to automatic and manual wind watches and its extreme accuracy.
An automatic watch is a watch whose mainspring is wound by the wrist movement of the wearer. The wrist movement of the wearer causes a rotor to turn and transmit its energy to the main spring to keep it wound. An automatic watch is self winding and does not require a battery. It is important to know that an automatic watch will stop if not worn for over a day, or if the wearer has been physically inactive for an extended period of time. Should this happen, wind the crown 20-40 times clockwise to start the watch and give it some reserve power. To keep an automatic watch running all the time even when not worn, the watch can be placed in a watch winder.
So, what is a reasonable expectation of accuracy from a wristwatch?
It is important to remember that even when a mechanical watch is allowed to vary +6/-4 seconds per day, that does not mean it will consistently vary by that high an amount each day. Mechanical movements--except the very rare 'turbillon' movements that correct for it--are noticably affected by the gravitational pull of the Earth. It only takes a performance distortion of 1/1000th of a percent for a watch movement to be one second less accurate in a day. This causes the performance of mechanical movements to be somewhat different from day to day when not stored in a fixed position. The good news is that the actual variations of a mechanical watch will often cancel each other out. This means a mechanical watch will tend to be more accurate over a longer period than the single-day COSC measurement may imply.
The day-to-day performance of quartz is much more consistent than mechanical under identical conditions. Quartz performance is affected mainly by temperature changes and weakened batteries. So a quartz watch that you measured to gains 0.5 second yesterday will be consistently increasingly off correct time by about that amount. You can be pretty certain that in 60 days, it will be about 30 seconds off. At the end of a year, it would be likely be over 180 seconds off.
While some people desire wristwatches with extremely high accuracy over long periods of time, it is seldom for any reason besides personal satisfaction. The few professions that depend on precision time synchronization (such as astronomy, global navigation, train scheduling, and broadcasting) base their operations on high precision time sources, not consumer wristwatches.
Ultimately, if you are living so close to the edge that having your watch off perfect time by less than a minute bothers you or otherwise throws your life into disarray, you probably need less caffeine and a vacation.
So why would anyone want a less accurate watch?
The short answer is that pretty much any modern wristwatch from a reputable brand is more than accurate enough for normal use. So some people choose to enjoy the esoteric, emotional and jewelry-value advantages of older mechanical watch technologies over the small accuracy advantages of quartz watches.
Make a difference by voting YES below and help make eBay a Better Place to Buy and Sell