Accuracy Pro Front View 45 Degree Inclination
Accuracy Pro acoustic measuring devices facing front
Accuracy Pro watch accuracy measurement tool side angle
Accuracy Pro watch accuracy acoustic measuring devices from above

Accuracy Pro - Acoustic Measurement Device

The ONEOF® Accuracy Pro is a high-end multi-position acoustic sensor for the measurement of mechanical watches. This device opened up a new era of innovation in the field of watch measuring instruments.

Purpose-built for Swiss Watchmaking

With our dedicated and powerful acoustic technology, our sensors perfectly meet the most stringent requirements of the Swiss watch industry.

  • Manual multiposition
  • 45° zero-backlash positioning
  • Smart locking System
  • Heavy watch locking system
  • USB-C plug & play
  • Anodized aluminum body
  • Sensitive piezoelectric sensor
  • Automatic gain control
  • 1ppm precision temperature compensated quartz oscillator (TCXO)
  • Integrated IMU with a 1° orientation detection
  • Cross-platform technology (Windows, iOS, macOS)

Breakthrough Technology Inside

As for all our professional acoustic measuring instruments, the electronic board of the ONEOF® Accuracy Pro is based on the premium XMOS micro-controller, a flawless hi-res USB audio processor.

  • Sensitive piezoelectric sensor
  • Automatic Gain Control
  • 1ppm precision TCXO
  • Cross-platform technology

Built to Last

The ONEOF® Accuracy Pro is made entirely in a high-grade anodized aluminum alloy. All sensitive elements potentially in contact with the external parts of the watch are coated with a soft-touch rubber.

  • Aluminium unibody
  • Soft-touch coatings
  • Sleek design

ONEOF® uses OM10 open source movement 3D data

Position Tracking

Linked with an Inertial Measurement Unit – a MEMS component that combines an accelerometer and a gyroscope – the device delivers real-time data about both the orientation of the watch and the signal of its escapement.

  • Integrated IMU
  • Zero-blacklash positioning
  • Realtime position feedback


H2i Application Screen

New Intuitive Interface

The Accuracy Pro comes with a newly developed Windows App which integrates all the features you need: realtime scope view, diagram display, dispersion over time, cumulated graphs, tabular and radar chart all in an intuitive and user-friendly interface.


Mounting of the mechanical watch on the Accuracy Pro measuring instrument

See How it Works for Yourself

Setup a demonstration with one of our sales representatives by filling in the form on the Get a Demo page.

Get a Demo


See all the features and specifications of the ONEOF Accuracy Pro has to offer on the product datasheet.

Download Datasheet
The Accuracy Pro professional watchmakers acoustic measuring devices

swiss logo

All H2i products are designed, manufactured and assembled in Neuchâtel, Switzerland. We have always taken special care to provide both high performance and user-friendly interfaces. All our software is developed in-house with the latest native programming languages.



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