Frequency, amplitude and testing
Frequency and amplitude
The balance and spring form the regulating oscillator; accuracy does not depend on them alone. Witschi defines frequency as complete oscillations per second, in hertz. One oscillation comprises two beats: 4 Hz equals 28,800 beats per hour. The nominal frequency remains a design reference; regulation slightly changes the oscillator’s actual rate. Witschi — testing methods for mechanical watches.
Witschi gives a typical amplitude of 270° to 310° for modern mechanical movements, horizontally positioned and fully wound. This is not a universal pass/fail threshold: limits depend on the calibre. Ageing lubricants can reduce amplitude; one reading proves neither the cause of a fault nor the movement’s health. A timing machine measures rate, amplitude and beat error and assists diagnosis. Witschi — testing methods for mechanical watches.
Incabloc dates its Swiss patent to 2 March 1933 and the start of production and its trademark to that same year; the lyre spring dates to 1938. These milestones should not be reduced to an invention in 1934. Incabloc — history.
Frequently asked questions
Why is my watch running fast or slow?
Rate depends on several factors; a timing measurement helps assess it.
Can a balance wheel break?
The reviewed sources cannot assess the risk for a particular model; have it checked after an impact.
What is the difference between frequency and amplitude?
Frequency counts oscillations per second; amplitude is the balance’s angle of movement.