The history of chronometer certification. These certifications are proof of watchmaking and chronometric excellence, with a sprinkle of savvy marketing. COSC will also test "watch heads" for wristwatches, but most manufacturers do not select this option.

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Already in the 18th century watches were tested in observatories for their accuracy. Today, the COSC functions as a sort of litmus test for precision throughout the Swiss watch industry.

The B55 doesn't appeal to me. I've been doing some research on COSC certification and can now see how the accuracy specifications demanded is in fact an engineering marvel. In an era when any watchmaker worth his salt has a timing machine (Witschi produces the most popular ones) that can measure accuracy immediately, the certification doesn’t necessarily have the same “wow” factor it once did.

A METAS certification is for the watch as a whole where as COSC only tests uncased movements for accuracy and temperature tolerances. Compare that to the -4/+6 per day for the uncased movement that COSC requires, or the 0/+5 Omega’s Master Certification.

). COSC’s job is to measure and certify the accuracy of mechanical watch movements, specifically to guarantee that a watch will run within +6 to -4 seconds per day. The COSC has exactly one function: to test, measure and certify the accuracy of watches. A chronometer (from Ancient Greek χρονόμετρον) is a specific type of mechanical timepiece tested and certified to meet certain precision standards. The 8 stringent METAS tests your timepiece must face to earn the title MASTER CHRONOMETER can only begin with movements already certified by COSC (Official Swiss Chronometer Testing Institute). Step 3. methods of measurement. A Guide to Swiss Watch Certification and Testing, From COSC to Chronometrique+ Many watches are certified, for various qualities like accuracy, durability and water-resistance, by independent agencies, ranging from COSC to TIMELAB. Watches without COSC-certification can still run within those tolerances, but that’s typically a matter of luck rather than fine-tuning. It is an independent public institution serving the Swiss art of watchmaking.

What is COSC? Seems it is a desperate attempt in part of Breitling to answer a question no one has asked in the face of the Apple Watch, which is a totally different animal altogether.

COSC actually peforms seven tests as part of the certification. The COSC Standard. Rolex has always had their own in-house, after COSC set of tests that they used to certify their time pieces to their own exact standards (it was always more of a functional ‘over-all’ watch test than one of better movement accuracy). The COSC Standard. Rolex’s continued commitment to testing and accuracy doesn’t just show they recognise the importance of reliability, but that they deem it vital to be more accurate … Certification. These certifications are proof of watchmaking and chronometric excellence, with a sprinkle of savvy marketing. the cosc The renowned Official Swiss Chronometer Testing Institute (“Contrôle Officiel Suisse des Chronomètres”, or COSC) was founded in 1973 and is based in La Chaux-de-Fonds, Switzerland.

Christopher Ward is no stranger to releasing COSC-certified timepieces.

I first felt -4/+6 or up to 10 seconds over ten days was a wide parameter, but it's not. Because the COSC certification has such prestige and reputation in the watch industry, many watch brands choose to include a line of text about it in the dial. Here's a handy guide to the most important Swiss watch certificates.

Acceptable tolerance time accuracy Page 1 of 2 1; 2 JLMedia Jan 19, 2016 ... One thing I will add: specifically for the Speedy Pro, it is not COSC certified thus the tolerance is -1 to +11 seconds per day.