Watch brands, journalists, enthusiasts, sellers and auctioneers often use these important watch terms incorrectly.
Common confusion
This should not be an opinion essay but a simple lesson on the correct definitions and accurate usage of the terms “precision” and “accuracy” in reference to watches. Unfortunately, misuse has become so prevalent in watch culture that it has become the accepted norm.
This confusion persists even among watch technicians. When I discuss these terms with them, they dismiss my concerns as those of a word nerd. One watchmaker even said to me, “You realize that doesn’t matter, right?” » I said, “Well, I think it's important.” » He replied with a laugh: “Yes, you think so. »
Precision vs. Accuracy: A Crucial Distinction
Understanding the definitions and correct usage of the terms “precision” and “accuracy” is essential for watch enthusiasts. We, enthusiasts, are by nature geeks seeking to understand the watchmaking arts in the smallest details. Speaking like experts can only strengthen our passion and understanding.
In her cultural history of clocks and watches in America, Marking Modern Times, history professor Alexis McCrossen highlights the importance of this distinction. She writes: “It is important for our understanding of horological time in the 19th century to distinguish precision and accuracy. An accurate clock measures and records the passage of time consistently. A clock set to the wrong time can still be accurate if it measures every second, minute, and hour correctly. An accurate clock, however, is set to the correct time. »
For example, a precision pistol always delivers the same propulsion and aim, while a precision shooter consistently hits his target. Calling the gun accurate seems absurd, just like calling the shooter accurate is incorrect. The gun is accurate (or not), and the shooter is accurate (or not).
Precision in watchmaking
This distinction is crucial in science. An accurate measuring instrument will produce reliable measurements with little or no deviation from test to test. A thermometer, for example, which gives inconsistent measurements would be useless. An accurate measurement, on the other hand, involves an accurate thermometer matching an external temperature reference. In science, as in life, precise instruments and exact measurements are prized, but they are not the same thing.
In the watch business, this confusion is common. We often hear that a watch is “very accurate” when it actually works consistently. However, to make this watch completely inaccurate, simply adjust it incorrectly. What we want from watches is not accuracy (which depends on us), but precision. If the accuracy is excellent, the watch will be accurate more often.
Certification programs and accuracy
Certification programs like Rolex's Superlative Chronometer, OMEGA's METAS-based Master Chronometer, and Chopard and Parmigiani's Foundation of Quality Fleurier promise a “precision chronometer.” This is the correct use of the term “precision”. But then we call our watch a “precision piece”.
The importance of linguistic precision
Once you understand these terms, you may find that the people you talk to watch people seem a little absurd. When someone says, “Hey, this new watch is super accurate,” I can't help but laugh inside, thinking sarcastically, “Wow, you know how to adjust your watch, well done!” »
There is a correct way to use the term precision for a watch. Once you set a watch to a standard time, it is accurate to the extent that its accuracy allows it to stay aligned with that standard. Every mechanical watch drifts noticeably, and when it does, it becomes inaccurate. So when people say, “accurate to +2/-2 seconds per day,” they are not entirely incorrect, provided the watch has been set correctly. The subtlety here is confusing, I agree. It is probably in this gray area that the tendency to mix terms was born. However, if you are describing the consistent (or inconsistent) performance of a watch, that is, if you brag or complain about your watch's ability to keep time, you are describing its accuracy.
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