"My watch is not accurate!" This is one of the everyday problems we have been grappling with for decades. It is one of the most complex to solve, in the face of which we need all the patience and expertise at our disposal, combined with a keen ability to comfort the customer with the right arguments, which our mastery of the subject leads us to list. The most difficult thing to convey is the concept that a mechanical watch, even if it is equipped with an excellent movement, and a robust case that protects it from the most common disturbing elements, is not immune to physical phenomena that more or less affect its precision. In the case where the mechanism is fine watchmaking, with a fine COSC (Swiss Official Chronometer Control) certificate attached, then our task becomes even more arduous. Often, the knowledge and expertise of customers is worth nothing, who, even though they know that a COSC certificate admits tolerances ranging from - 4 to + 6 seconds per day (let us avoid a description of the method used to obtain such a certificate), firmly and insistently ask us to entrust the watch to technicians in order to hope for the miracle of almost absolute precision. Incidentally, it must also be said that some leading manufacturers indicate as good, on the instruction booklets for non-COSC-certified watches, on the 'precision tolerance' page, a deviation of - 1 + 11 seconds per day. Many particularly meticulous enthusiasts arrive in the shop with specific and meticulous documentation in tow, consisting of tests carried out by them personally, with positive and negative values recorded every 24 hours over a period of days (for this purpose, the 'Precisometer' sheet, published every year by l'Orologio, proves very useful). But when you try to make them understand that the tolerances recorded fully meet the right parameters for their watch, with a piercing look they ask you to do even better. It has to be said that the subject of 'precision' should be dealt with comprehensively at the time of sale, so as to dispel any doubts afterwards, but sometimes even this is not enough. And so, having made this dutiful introduction to the problem, I intend to inform readers (as if it had not already been done a thousand times on these pages but, as experience teaches, repetita iuvant) that 100% precision does not exist in a mechanical watch, be it manual or automatic winding, chronograph or perpetual calendar. The watch is exposed on a daily basis to a series of factors that determine its precision, such as variations in outside temperature, sources of humidity, electromagnetic fields, long motorbike rides on the rutted city streets, and then the habitual positions that the wrist of each of us assumes during the course of a day... In short, a whole series of things that mean that the same type of mechanical watch worn by me does not offer the same performance as that worn by a caver! Believe me, it is not a question of materials or components, which although they have reached incredible levels of quality, with countless innovations covered by patents, will never allow the absolute 'split-second', due to the very nature of the physical phenomena that govern and influence the functioning of the mechanical watch. For high precision, technology invented the quartz watch and, as with everything in the world, it is a matter of choice.
