What daily rate tells you, how to collect useful readings, and how to put a surprising number in context.
Look at both how much time your watch gains or loses and how consistently it does so. A single reading tells you how far ahead or behind it is. Repeated readings tell you whether that offset is growing or shrinking.
The daily rate expresses that gain or loss in seconds per 24 hours. Compare it with the manufacturer's specification for your watch, while keeping track of the conditions and uncertainty of your measurements.
| Look at | What it helps you understand |
|---|---|
| Daily gain or loss | How the watch kept time across the measured interval, compared with its specification. |
| Repeated readings | Whether a pattern persists rather than depending on one observation. |
| Measurement conditions | Whether differences could reflect position, winding state, the reference or your recording method. |
A number inside a published chronometer range does not certify a watch. Certification involves defined testing; the app's colors and Chronometer Score are summaries of your readings, not certification results.
Manual drift tracking and acoustic measurement answer different questions. Knowing which one you are looking at makes the result more useful.
Save the offset between the watch's hands and your reference, let time pass, then save another reading. The change in offset divided by elapsed days gives the average daily rate across that interval. For example, returning the next day provides a more useful interval than tapping twice a few moments apart.
Both readings must belong to the same uninterrupted session. If the watch stops, is serviced or you reset its hands, begin a new session before comparing subsequent readings. In Chronograde, starting additional sessions is a Pro feature; plan your first free series while the watch keeps running.
Chronograde queries public time servers and uses a network correction when one is available and usable. It otherwise labels readings made from the device clock. Network conditions, reference quality and the timing of your RECORD tap all affect the result; there is no guaranteed fraction-of-a-second accuracy. Repeat the method consistently and review several separated readings rather than assuming errors will cancel out.
A timegrapher analyzes a mechanical watch's ticking to estimate rate and beat error. This is a snapshot in one position and at one state of wind; it does not measure the watch's entire day on your wrist.
A phone microphone needs a usable signal. Background noise, movement, placement and an incorrect BPH setting can affect the estimate, and some watch/device combinations may not yield a reading. There is no fixed time in which a reliable result is guaranteed.
Use the acoustic snapshot alongside the longer-term drift history. Neither result alone establishes that a movement is healthy or tells you which physical repair it needs.
Beat error describes an asymmetry in the timing of alternating beats, expressed in milliseconds. It is different from a watch's daily gain or loss. A noisy phone recording can produce an unreliable estimate, so repeat a surprising result before drawing conclusions. A watchmaker can assess a persistent concern using equipment and procedures suited to the movement.
First check the measurement: a clear acoustic signal and correct BPH, or separated manual readings with the right time, reference and session. Repeat under similar conditions. If a large or persistent change remains, bring the history and your observations to a watchmaker; a phone estimate cannot decide whether regulation, service or another intervention is appropriate.
Download Chronograde on the App Store for iPhone and iPad. The acoustic Timegrapher is free, as are your whole collection, up to ten manual accuracy measurements, one complete Regulation Coach run, iCloud sync and backup/restore.
For acoustic readings, use a quiet room and keep the watch and device steady on a soft, stable surface. Bring the microphone close gently; do not press, drag or force the device against the watch. Follow the first-readings guide for both measurement methods.
Pro adds unlimited manual measurements, additional sessions, repeat Coach runs, Accuracy by Position, the app's Chronometer Score, the Atomic Clock display, wear/service logs and spreadsheet import/export. It also removes advertising while Pro is active. Monthly and annual subscriptions and a one-time Lifetime unlock are available; see in-app localized pricing and any eligible subscription trial before buying. Premium themes are separate purchases. See the full free/Pro comparison, chronometer standards guide and caliber reference.