TECHNICAL GUIDE
Cal. 4R15A/4R15B/4R16A/4R16B
15/19
REGULATION
●
Names of the parts for regulation and their functions
[StUD SUPPORt]
Correction of the beat
error by positioning the
roller jewel correctly
[RegULAtOR]
Regulation of the accuracy rate (+) or
(-) by adjusting the operative length
of the balance-spring
[StUD (glued at the balance-spring)]
Alignment of the balance-spring to the
center of the regulator pin's slit
[RegULAtOR PiN]
Adjustment of the play of the bal-
ance-spring embraced in its slit
●
How to regulate the isochronism fault by adjusting the position of the balance-spring
this caliber has the etachron system for fi ne regulation of the isochronism fault,
which is the same
design used for both Cal. 7S-B series and 6R series.
When an amplitude of the balance becomes weak, the watch shows time loss, in general.
By making a clearance of the balance-spring smaller, the decline curve of the instantaneous rate
gets shallower.
1) Make sure that the RegURAtOR PiN is aligned in a vertical position to the RegURAtOR and the
balance-spring passes parallel through the slot of the RegULAtOR PiN before fi ne-tuning the StUD
and the RegULAtOR PiN.
RegULAtOR PiN
top side view
back side view
angled view
1
2
3
4
1
2
3
4
2
RegUlation
