Seiko 4R37A Technical Manual

Parts List / TECHNICAL GUIDE

[SPECIFICATIONS]

Item
• 3 hands
(hour, minute and second hands)
• Date indication
• 24-hour indicator
Outside diameter
Movement size Casing diameter
Height
Driving system
Time indication
Additional function
Normal position
Crown
1st click position
operation
2nd click position
Vibration per hour
Daily rate worn on
the wrist at
temperature range
between 5 °C and
35 °C)
Loss/Gain
Standard rate for
measurement
Regulation system
Lift angle of the escapement
Power reserve
Number of jewels
Automatic Cal. 4R37A
Cal. No.
• 3 hands
(Hour, Minute, and Small second hands)
• Date indication
• 24-hour indicator
• Date correction function
• Second hand stop function
Mainspring wind
up status
Testing positions
Measurement
(daily rate in
seconds: s/d)
4R37A
Movement size
• Diameter
Outside:
Casing:
• Height:
Ø 27.4 mm
Ø 27.0 mm
5.32 mm
Automatic winding with manual winding mechanism
Manual winding (clockwise only)
Date setting (counterclockwise)
Time setting (Hour and minute), Second hand stop
21,600 (5 beats per second)
Between +45 and -35 seconds
Fully wind up
Dial upward:
6 o'clock at the top 9 o'clock at the top
T0 (CH)
± 20 s/d ± 30 s/d
ETACHRON System
53 °
From fully wound to stoppage: Approximately 40 hours
24 jewels
Ø 27.4 mm
Ø 27.0 mm
5.32 mm
After 24 hours
from fully wind up
Dual upward:
T24 (CH)
(Isochronism
± 30 s/d fault: T24-T0)
± 30 s/d