How to Read a Timegrapher
A timegrapher is a tool that measures the accuracy and health of a mechanical watch movement. Here’s how beginners can use one to check their replica.
What is a Timegrapher?
A timegrapher listens to the “tick” of your watch and displays key metrics:
- Rate: How many seconds per day your watch gains or loses.
- Amplitude: The strength of the balance wheel’s swing (higher is better).
- Beat Error: The difference in timing between the tick and the tock (lower is better).
Key Metrics: Beat Error, Amplitude, Rate
| Metric | Good Value | What it Means |
|---|---|---|
| Rate | -10 to +10 s/day | Closer to zero is better |
| Amplitude | 250–320 degrees | Higher = healthy movement |
| Beat Error | <0.6 ms | Lower = better |
Table: Example Timegrapher Readings
| Reading | Result | Interpretation |
|---|---|---|
| +8 s/day | Good | Slightly fast |
| 280° amplitude | Good | Strong movement |
| 0.3 ms beat error | Excellent | Well adjusted |
How to Use a Timegrapher
- Place your watch on the microphone.
- Select the correct lift angle (usually 52° for most movements).
- Wait for the readings to stabilize (about 30 seconds).
- Record the rate, amplitude, and beat error.
Interpreting Results
- If your watch is gaining/losing more than 15 seconds per day, consider regulation.
- Low amplitude or high beat error may indicate a need for service.
FAQ
1. Is a timegrapher necessary for all reps?
No, but it’s useful if you want to check accuracy or troubleshoot issues.
2. What readings are acceptable?
Aim for rate within ±10 s/day, amplitude above 250°, and beat error below 0.6 ms.
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