Buying guide
Buying a used measuring machine: CMM, profile projector, height gauge
Published on October 13, 2026
A used coordinate measuring machine or inspection instrument can be an excellent deal, provided you check the measurement uncertainty, the software and its licences, and plan for calibration after installation.
In metrology, you are not just buying a machine: you are buying the ability to measure with a known uncertainty. The price of a used coordinate measuring machine (CMM) depends as much on its software, its probe and its calibration records as on its mechanics.
The right instrument for your parts
- Coordinate measuring machine: measuring volume, maximum workpiece weight, stated maximum permissible error (MPE, according to ISO 10360).
- Profile projector or optical measuring machine: field of view, magnifications, edge detection software.
- Height gauge: travel, resolution, calculation functions; several Swiss manufacturers offer them.
- Surface roughness tester, form or roundness measuring instrument, depending on your requirements.
Software and licences
This is the most common pitfall. Measuring software is often tied to a named licence or a hardware dongle, and transferring it to a new owner may involve a fee, or even be impossible. Ask for the version, the options included (scanning, profile measurement, gears…), whether the dongle is present and the manufacturer's written agreement to the transfer. Also check compatibility with a current computer and operating system.
Probe and accessories
- Probe head: fixed or indexable, touch-trigger or scanning probe, condition of the connectors.
- Probe change rack, extensions and styli supplied.
- Reference sphere with its certificate, gauges and fixtures.
Mechanics and environment
On a CMM, inspect the granite table (chips, stains), the guideways and the air bearings: they require clean, dry compressed air. Movements must be smooth and quiet. Plan for a room with a stable temperature, ideally close to 20 °C, protected from vibration: a precise machine installed in the middle of the shop floor will not hold its performance.
Calibration and records
Ask for the latest calibration certificate, its date and the laboratory that issued it. After dismantling and transport, a new calibration is essential: budget for it from the outset, preferably by an accredited laboratory or the manufacturer's service team.