Regulating changes a movement's rate; it does not repair wear, magnetism, poor lubrication or damage. First establish what the watch is doing under consistent conditions. If it is valuable, under warranty, or far outside the maker's stated accuracy range, use an authorised service centre or qualified repairer.
Measure a useful average
Set the watch against a reliable time reference and record the difference at the same time each day for about a week. Keep the winding routine and wearing or resting position as consistent as practical, and note unusual shocks or temperature changes. Seiko explains that mechanical-watch accuracy varies with position, wear, winding and conditions, and is assessed using daily rates over about a week rather than one isolated day. A single day's result is not a diagnosis.
| Observation | Consider before adjustment |
|---|---|
| Small change from day to day | Continue recording under similar conditions |
| Rate changes when resting in different positions | Record the positions and compare averages |
| Sudden large gain or loss | Consider magnetism, shock or a fault; seek assessment |
| Poor running, stopping or erratic behaviour | Stop and arrange service |
Citizen likewise notes that winding, position, temperature, magnetism and shock can affect a mechanical watch. If the watch has been near a strong magnet or suffered an impact, moving a regulator is unlikely to address the underlying issue.
What a regulator adjustment involves
Movement makers publish technical guides for specific calibres. The Time Module NH35 series guide identifies distinct regulator and beat-error adjustments, which is a reminder that “regulation” is not one universal screw or procedure. Do not infer adjustment direction from a photograph or transfer instructions from another calibre. A small movement can be damaged by a misplaced tool or uncontrolled adjustment.
A timegrapher can help a trained user observe rate and other readings in defined positions, but it cannot by itself prove that a movement is healthy or that a watch is sealed. If you are learning, use an expendable training movement and the exact maker's technical guide. Get practical instruction before working on an assembled watch.
Opening a watch can void its warranty and its water resistance. Water-resistance testing needs proper equipment. If you do not have the right documentation, tools and experience, record the timekeeping and give those notes to a repairer. See the starter tools guide before buying a timegrapher or drivers.
Sources & further reading
- Seiko: accuracy of mechanical watches · Checked 2026-10-25
- Time Module: NH35 series technical guide · Checked 2026-10-25
- Citizen: basic understanding of mechanical watches · Checked 2026-10-25