Series 31
The pocket watch movement that has been redesigned to feature an indirect central second hand makes this watch an elegant choice. A key feature of the movement remains the secret of the wearer – the second stop.
To precisely set the time of a wrist watch most movements are equipped with a second stop – when the crown is wound, the second hand doesn’t move. The seconds zeroing is a much rarer design.
When the crown is wound, the second hand continues to run until it reaches “60” and then it automatically stops – thus it is possible to use a time signal to set the watch to the second.
Model Overview Series 31
31.HS-12.1
Bezel
fixed bezel
Case
stainless steel polished, case sides in satin finish
Dial and Hands
deep black dial, hands made in steel
Special features
Nivarox hairspring, swan neck micrometer
31.HS-12.2
Bezel
fixed bezel
Case
stainless steel polished, case sides in satin finish
Dial and Hands
deep black dial, hands made in steel
Special features
Nivarox hairspring
31.HS-14.2
Bezel
fixed sandblasted bezel
Case
stainless steel bead-blasted
Dial and Hands
deep black dial, hands made in steel
Special features
Nivarox hairspring
Technical details
Movement
- Calibre HS 81
- Base: UNITAS 6497 Lépine. Modified as per a construction by Helmut Sinn
- indirect center second
- second stop at 60 when crown is pulled
- 18 jewels
- 18000 vibrations per hour; 2.5 Hz.
- Movement diameter 16 1/2''' (36,6 mm)
- Incabloc shock protection
- Glucydur balance
- Nivarox hairspring
- Movement decorated with Geneva Stripes , blued screw hads, crown wheel and ratchet wheel with solar finish
- Power reserve approx. 40 hours
Functions
- Hours, minutes, indirect center second
- Second stop at 60 when crown is pulled
Case
- Case made of stainless steel, polished
- sapphire crystal glass, anti-reflective on the interior
- screwed back with crystal glass
- Pressure resistant up to 10 bar
Dimensions and Weight
- Case diameter: 41.9 mm
- Case thickness: 13.7 mm
- Band lug width: 22 mm
- Weight without strap: 71 Gramm