As we all know, Bremont watches are made to be 'Tested Beyond Endurance' but this begins in the watchmaking facility. Every single Bremont watch goes through rigorous testing before leaving HQ whether for sale or following customer servicing.
I had a great chat with Stuart Duff the head watchmaker today ( see his 'meet the team' tomorrow ) and we spoke about the testing period of watches and the elements within it. I thought I would therefore do an A-Z series to give some more information on the various processes that go in to Bremont watchmaking and testing.
First up; Amplitude
A very important part of the testing process is Amplitude and it is generally where the watchmakers start.
Amplitude is basically the 'heartbeat' of the watch and is the measurement of rotation in the swing of the balance wheel in either direction usually given in degrees. At '0' hour the amplitude of a watch generally must not exceed 310 degrees at its highest reading. Amplitude can be affected by various issues including but not exclusive to problems with the movement, magnetism, lubrication etc. Generally, a watch with a low amplitude will tend to gain time for example in the case of a magnetised balance spring. Irregularities in the amplitude can be highlighted by problems with the timekeeping so it is imperative that this element is correct and checked thoroughly. When looking at the condition of a watch amplitude is generally the most important factor.
When testing watches before being sent out Bremont use a Cyclomat or 'Windmill' ( see pic below. ) With no power in the mainspring, the watch is placed on the Cyclomat for an initial period of 6 hours for a chronograph and 4 hours for a 3 hand watch where it turns continuously in several directions, this will test the watches automatic winding ability.
Following this period the watch is tested on a Chronoscope. The Chronoscope is a highly sensitive machine that measures the amplitude and timekeeping ( amongst other things ) of the watch in 5 different positions; dial up, dial down crown down, crown up and crown to the side. Following this test a reading is given in all the positions and a mean average is taken - this is where we get the -4 +6 seconds per day variant that runs within COSC specifications.
At this point, if the watchmakers are happy, the watch is set to the atomic clock and then placed dial down for 24hrs. It is then checked again against the atomic clock and re placed on the chronoscope. The lowest amplitude reading at this point should not be below 220 degrees. From here, the watch is then allowed to power down. The time taken for this to occur is then recorded to ensure the power reserve is working correctly.
All watches following service are tested over a 15 working day period to make sure that the power reserve and automatic winding elements of the watch are working perfectly before being sent out.
This of course is just one element of the testing process, but please feel free to post comments and questions.
S
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Originally Posted by Oracle
