Could your watch be magnetised? Investigating a sudden rate change

Magnetisation can affect a mechanical watch, but it is not the only explanation for suddenly different timekeeping. Observe the pattern and circumstances before repeatedly trying to demagnetise it.

How a field can interfere

Ferromagnetic components can be affected, and changes involving the hairspring may disturb normal oscillation. Results depend on construction, materials and the exposure. Quartz watches are not universally immune either; their drive and other components can also be affected.

Record the surrounding conditions

Note contact with speakers, magnetic accessories or closures, alongside reserve, wearing pattern and the time the change began. Phone sensor apps are influenced by distance, surrounding metal and the device itself. They can provide clues, not definitive diagnosis.

Testing and follow-up

Suitable equipment and experience can establish and address magnetisation, after which timekeeping should be observed again. Continued problems, unusual noise, stopping or an impact history require further investigation. Do not open the movement or try to counter a magnet with another strong magnet.

Common misunderstandings

Low reserve, environmental changes, impacts and other mechanical conditions can also alter the rate. An instantaneous instrument result is not the end of the investigation. Check behaviour again during normal use.

Your practical checklist

• Record conditions before and after the change.
• Treat phone measurements only as clues.
• Investigate further if abnormal behaviour continues.