ETA 2671

ETA is the Swiss movement house owned by the Swatch Group, whose calibers power a large share of mechanical watches across every price tier.

01Specifications

02What these specifications mean

Frequency is how fast the balance wheel swings, counted in vibrations per hour (vph) or in hertz (Hz), where one hertz equals two vibrations. A higher frequency means the escapement divides time into finer slices, so the watch tends to keep a more stable rate and resists small shocks better. It also means the tick the timegrapher hears arrives more often, which the analysis uses to lock onto the beat.

The lift angle is the arc, in degrees, that the balance wheel travels while the pallet fork is engaged and pushing it. A timegrapher cannot see the balance directly; it only hears the tick, so it must be told the lift angle to convert the timing of those ticks into an amplitude reading. Enter the wrong lift angle and the rate stays correct but the amplitude figure is off by several degrees.

The power reserve is how long the movement runs from a full wind until it stops. As the mainspring unwinds its torque falls, amplitude drops and the rate usually drifts, which is why a watch can read differently at full wind versus near the end of its reserve.

03Measuring this caliber with WatchScope

The lift angle of this caliber is not officially published, so use 52° as a safe default in WatchScope before you start. Rest the watch against the phone microphone in a quiet room, pick a position and let the reading settle for a few seconds. The rate will be accurate either way; only the amplitude figure depends on the lift angle, so refine it if the maker later confirms a value.

Frequently asked questions