> For the complete documentation index, see [llms.txt](https://rwi-watches.gitbook.io/rwi-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://rwi-watches.gitbook.io/rwi-docs/how-to-read-timegrapher-numbers.md). # How to read timegrapher numbers Understand rate, amplitude and beat error in a watch QC recording, including lift-angle settings, test conditions and a worked clarification example. A timegrapher recording helps you ask how a mechanical watch was running during a particular test. Read the figures together with the watch position, measurement settings and recording conditions before using them in a QC decision. For an order review, you usually need a clear recording and an explanation of any unusual result. You do not need to buy a timing machine to request that information from the seller. ## What the main figures mean | Display | Plain-language meaning | Question to ask | | ---------------------- | ---------------------------------------------------------------------------- | ----------------------------------------------------------------------------- | | Rate, usually s/d | The measured rate deviation, expressed in seconds per day | Which position and measurement interval produced it? | | Amplitude, in degrees | The balance wheel's swing from its equilibrium position to its turning point | Was the correct lift angle used for this movement? | | Beat error, usually ms | A measure of asymmetry in the balance oscillation | Is the reading stable, and how does it compare with the applicable tolerance? | These definitions are explained in [Witschi's training course on watch measurement, pages 7 and 8](https://www.javiergutierrezchamorro.com/wp-content/uploads/2022/06/amplitud_lift_angle_beat_error_witschi_training_course.pdf#page=7). The linked copy is hosted by a third party. We use its explanation of measurement principles; it does not set an approval standard for the watch you are ordering. ## Read the settings as well as the result **Lift angle** is an input used for amplitude measurement, as described in the same Witschi training course. If it is missing or inappropriate for the movement, ask the operator to confirm it before interpreting the amplitude. **Beat rate** is the frequency setting or detected beat number. A matching number alone does not identify a movement. Witschi's [ChronoMaster specifications](https://www.witschi.com/en/products/chronomaster-2/) show that beat rate, lift angle and test position are separate parts of the measurement setup. For a useful QC record, ask the seller to show the watch and the display in one recording where practical, or explain how the recording is tied to your unit. Save the original file instead of only a cropped screenshot of three figures. ## A practical reading sequence 1. Identify the proposed unit and the movement description supplied by the seller. 2. Read the rate, amplitude and beat error without treating any single figure as the verdict. 3. Check which position was measured and what settings are visible. 4. Ask about the winding state and whether the reading had settled before the recording. 5. Request clarification or a repeat measurement when a result or its conditions are unclear. 6. Save the result alongside the visual QC checks and the seller's explanation. The WAIO manual describes a sequence of positions with settling time before measurement. It also instructs its operator to check winding and repeat the measurement when amplitude is very low. Those are useful reasons to ask about the test conditions before drawing a conclusion from one screenshot. [Witschi operating instructions, pages 42 to 49](https://www.hswalsh.com/usercontent/doc/30780/HWAIO%20-%20Witschi%20WAIO%20Operating%20Instructions.pdf#page=42). ## A worked example The following numbers are fictional and illustrate how to record a question. They are not acceptance limits or a report from a customer's watch. | Recorded item | Fictional example | | ---------------------------- | ----------------------------------------------- | | Unit reference | Example QC set A | | Rate | +6 s/d | | Amplitude | 270 degrees | | Beat error | 0.2 ms | | Position | Seller says dial up | | Lift angle and winding state | Not supplied | | Next action | Request the settings and measurement conditions | The useful reply is: “Please confirm the movement description, lift-angle setting, winding state and position for this recording. Was the reading stable during the test, and which tolerance are you using to assess it?” That request fills the gaps. It does not declare the watch acceptable or defective from an incomplete record. ## What are good timegrapher numbers? Ask which movement-specific tolerance or documented inspection standard is being applied. A table of generic thresholds copied from an unrelated movement can give a misleading answer. Keep the stated tolerance beside the measured result so the comparison is visible. A value close to zero on the rate display is one observation from the test. It does not establish the condition of every component, authenticate the movement, or replace the rest of the [QC checklist](/rwi-docs/replica-watch-qc-checklist.md). ## Does this predict the watch's performance after delivery? Treat the recording as a dated part of the order evidence. It is not a guarantee of a fixed daily result throughout ownership. If performance after delivery is a concern, save your observations and contact the seller through the agreed [after-sales process](/rwi-docs/seller-terms-and-delivery-checklist.md). Record the seller's answer and the test reference in the [watch order and QC template](/rwi-docs/watch-order-and-qc-template.md). --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://rwi-watches.gitbook.io/rwi-docs/how-to-read-timegrapher-numbers.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.