Patek Philippe CALIBER 240 PS IRM C LU, User Manual

Page: 17 / 114

17
quality control
The movements and completely assembled watches
are subject to a series of technical tests and visual
inspections to verify their rate accuracy, winding
speed, power reserve, reliability, water resistance,
and overall appearance. After it was assembled,
your self-winding watch will already have run for
several weeks before leaving the workshops; it
fully complies with the stringent criteria of the
Patek Philippe Seal.
rate accuracy
The rate accuracy of Patek Philippe watches is
verified in several phases of manufacturing, both
with uncased and fully cased movements. The final
test is performed with a wrist motion simulator
and the results must conform to the following
Patek Philippe precision benchmarks:
The rate accuracy of calibers with a diameter of 20 mm or
larger must range within – 3 and + 2 seconds per 24 hours.
The precision of a watch is determined by how
accurately it keeps the time. A watch that is fast
or slow is considered precise if the amount by
which it is fast or slow remains constant. Such
a deviation can be easily corrected. The last test
of accuracy takes place on your wrist. Your tem-
perament or the nature of your physical activities
can cause slight irregularities. Fluctuations in posi-
tion, temperature, or air pressure, the presence of
magnetic fields (as produced by most electronic
devices, metal detectors, household appliances,
etc.) as well as vibrations and other factors may
also affect its accuracy.