Behind every tick-tock lies a precision that only a timegrapher can measure. By capturing the sound impulses of the balance wheel via its integrated microphone, it translates this rhythmic language into three fundamental indicators: rate, amplitude, and beat error. In a few seconds, without disassembling the movement, the timegrapher provides a complete mechanical diagnosis, telling you exactly what your watch has to say.

What is a timegrapher and how to use it?

A timegrapher, also known as a watch timing machine, is a measuring device that analyzes the sound produced by the balance wheel of a mechanical watch. Its use is simple:

1. Place the watch facing the timegrapher's microphone, dial side up to start.
   
2. Select the lift angle corresponding to the movement's caliber. You can find it in our Lift Angle tool.
3. Wait 20 to 30 seconds for the values to stabilize before recording them.
   
   

Timegrapher — The Rate: how many seconds per day?

This is the most intuitive parameter: the rate indicates how many seconds per day your watch gains or loses. It is expressed in seconds per day (s/d), with a positive sign (+) when the watch gains time, and a negative sign (−) when it loses time. A watch showing +3 s/d will gain approximately 21 seconds over a week.

Reference thresholds:

Value	Interpretation
0 to ±7 s/d	Excellent Level required by COSC certification, which accepts between -4 and +6 s/d.
±7 to ±15 s/d	Very satisfactory Quite respectable for a vintage mechanical watch.
±15 to ±30 s/d	Acceptable A service may be considered.
Beyond ±30 s/d	Service recommended

 

Please note: a vintage mechanical watch, even in perfect condition, will never compare to the precision of a quartz movement. This is precisely what makes it charming – each mechanical movement is alive, slightly imperfect, and unique.

 

Timegrapher — The Amplitude: the pulse of the movement

Amplitude measures the angle of rotation of the balance wheel with each oscillation, expressed in degrees. A generous amplitude indicates a well-lubricated movement, free in its momentum, a sign of careful maintenance and a healthy mechanism. A low amplitude, conversely, reveals excessive friction, often due to old lubrication that needs to be renewed.

Values recorded with the watch fully wound.

Value	Interpretation
280° to 320°	Excellent Movement in very good condition, well-lubricated.
250° to 280°	Very good Normal operation.
200° to 250°	Acceptable A service is advisable in the medium term.
Below 200°	Service needed

 

Timegrapher — The Beat Error: the symmetry of the balance wheel

Beat error is the least intuitive parameter, but one of the most revealing of the quality of a movement's adjustment. It measures, in milliseconds, the difference in duration between the "tic" and the "tock," in other words, whether the balance wheel oscillates perfectly symmetrically in both directions, or if one side takes slightly longer than the other.

Ideally, this value should be 0 ms. In practice, a slight asymmetry is normal and acceptable.

 

Value	Interpretation
0.0 to 0.3 ms	Excellent
0.3 to 0.5 ms	Very satisfactory Negligible asymmetry, with no measurable impact on precision.
0.5 to 1.0 ms	Acceptable Impact on precision is generally minimal.
Beyond 1.0 ms	Correction needed

For vintage watches, a beat error value slightly higher than that of a new movement is common and not in itself a deal-breaking flaw, especially if the rate and amplitude are satisfactory.

 

Reading the Results as a Whole

A timegrapher result is not deciphered indicator by indicator, but in its entirety. It is the combination of rate, amplitude, and beat error that provides a complete picture of a movement's condition.

• Correct rate • High amplitude • Low beat error: movement in excellent condition, perfectly maintained.
• Correct rate • Low amplitude: the watch works, but a service will eventually be necessary. Lubrication is probably insufficient.
• High beat error • Low amplitude: sign of friction or an internal geometric problem. Consultation with a watchmaker is recommended.
• Irregular graphical line / scattered dots: The movement lacks consistency. May indicate contamination, magnetization, or a more serious problem.