ISA Speciality 8171/204 Electronic Chronograph Quartz Movement

Technical specifications manual for the ISA Speciality 8171/204 electronic chronograph quartz movement. This workshop reference details a patented dual-rotor motor paired with rotating stepping motors that drive the chronograph and timekeeping functions. The movement features a running seconds hand advancing at 1 step per second, a central chronograph hand operating at 5 steps per second, and a 30-minute counter with automatic stop and reset after 2 hours of continuous operation. Additional functions include rapid-correction date display and moonphase indicator. The manual provides mechanical drawings with precise dimensions and fitting tolerances for case, dial, and hand assembly—essential reference material for watchmakers and repair technicians. Operating specifications: 1.55V battery (SR 927 SW format), 1.35µA current draw in timekeeping mode and 12.0µA with chronograph active. Temperature range 0 to +50°C; movement resists magnetic interference up to 1500 A/m. Battery life approximately 57 months under typical use with one hour of daily chronograph operation. Includes all technical data necessary for movement service, parts replacement, and functionality verification.