Arnold & Son A&S dial-side true beat

Probable

Records a construction rather than a specification, because the construction is what an examiner uses. Placing the mechanism on the dial side means the complication's cause and its effect are visible together — the hand steps and the mechanism driving it can be watched doing so, which is a stronger form of evidence than either alone.

Specifications

Movement manufacturer: Arnold & Son
Winding: manual
Complications: True-beat seconds

Architecture

A manually wound caliber with a true-beat (dead-beat) seconds mechanism mounted on the DIAL side, so the lever, wheel and spring producing the one-second steps are visible from the front.

Authentication notes

MovementProbable
Distinguish a true beat from a quartz step
Both advance the seconds hand once per second, which is the point worth being careful about: a stepping hand is not by itself evidence of a true-beat mechanism, since the cheapest possible substitution produces the same visible result. On this reference the mechanism is exposed on the dial side, so the two can be told apart directly — watch the lever and wheel drive each step. A hand that steps with no visible mechanism behind it is the finding.

Service practice

La Joux-Perret work. A dial-side mechanism means servicing involves the front of the watch, and any disturbance to the exposed components is visible in a way that work on a concealed movement is not.

References using this caliber

Arnold & Son DSTBFactory
Instrument · Whole production

Provenance of this record

Sources & Evidence

Primary sourceManufacturer documentation

Arnold & Son — collection and caliber specifications

Arnold & Son (Citizen group / La Joux-Perret)

Accessed: 2026-08-19

Cited for

This referenceHigh confidence

View source ↗

Secondary sourceSpecialist publication

Specialist coverage of Arnold & Son's dial-side movement architecture

Established horological publications

Accessed: 2026-08-19