Jun 16 20:26 2018, Björn Felten wrote to Alexey Vissarionov:
BF> Quartz oscillators are priced by their precision. The cheapest are BF> sold to Asian watchmakers, the more precise they are the more BF> expensive they become. The most expensive ones are sold to the Swiss BF> watchmakers.
I think you're talking about quartz crystals, i.e. the classic 32.768kHz watch crystal. A quartz oscillator is the crystal plus an oscillator circuit. For a precision time source you would take a TCXO or go for a rubidium standard which aren't used for typical watches. Of course quartz crystals got different tolerances based on the quality and type of cut, but the frequency drifts with temperature. Hence the TCXO. It doesn't make much sense to buy a quartz crystal with a very low tolerance at a specific temperature when the temperature can't be controlled, like in a wrist watch.
