IWC Schaffhausen 5902 Mode D'emploi page 18

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T H E T E C H N I C A L R E F I N E M E N T S O F T H E
P O R T U G I E S E R C O N S T A N T - F O R C E T O U R B I L L O N
Your IWC watch shows you the time in hours, minutes and seconds,
together with the moon phase and the power in reserve. The hand­
wound mechanical movement has a power reserve of approximately
96 hours when fully wound. Your Portugieser Constant­Force Tour­
billon is protected by a sapphire glass of hardness grade 9 on
Mohs' scale. Your watch is water-resistant 3 bar. Furthermore, it
is equipped with a minute tourbillon, a unique micro mech anism,
which minimizes the effect of gravity on the rate precision. The
constant­force mechanism, which is housed directly in the tour­
billon, ensures consistent amplitude over at least 2 days. This is
indicated by the one­second jumps of the seconds hand on the
tourbillon. If the energy in the two barrels is insufficient to main­
tain the constant­force mechanism, the watch rate automatically
switches to 2.5 hertz. This can be seen in the fact that the seconds
hand on the tourbillon is now moving constantly. This rate corres­
ponds to that of a standard tourbillon.To ensure that this extra­
ordinary watch continues to perform faultlessly in the future, it is
essential to observe a few important operating instructions.
P O R T U G I E S E R C O N S T A N T - F O R C E T O U R B I L L O N