Standardised specification and testing of modern multi-sensor coordinate measuring systems

In the field of coordinate metrology two important ISO standardization project could be brought to a first milestone.

Since a couple of years, the working group ISO TC 213 WG10 Coordinate Measuring Machines work at establishing an international standard for the acceptance and reverifcation testing of coordinate measuring systems (CMMs) using computed tomography (CT) as the single sensor.

The technical basis of this work was the national guideline VDI/VDE 2630-1.3 “Computed tomography in dimensional measurement - Guideline for the application of DIN EN ISO 10360 for coordinate measuring machines with CT-sensors“, which was published in 2011 by the German VDI/VDE-GMA technical committee “Computed tomography in dimensional metrology”.
After passing through a series of pre-states, now at the first time a public draft ISO/DIS (DIS – draft international standard) will become available.

This ISO/DIS draft settles for the first time

• the specification for three different material classes (plastic, aluminium, steel),
• the use and the notation of preknowledge about the measurement task,
• the application of obstructive bodies for the tests of the probing errors,
• the definition of additional optional characteristics (for probing error testing and for the bidirectional length measurement error testing) and
• the assessment of the test value uncertainty for test measurements.

The DIS draft will be commented in the predefined ISO balloting procedure and will lead to the ISO 10360-11 FDIS draft (FDIS – final draft international standard).

For the optical 3D CMSs, such e.g. optical measurement systems featuring structured light illumination, for the same purpose ISO 10360-13 will be published as FDIS. Here the technical basis were national standardisation activities of the German VDI/VDE-GMA technical committee “Optical 3D metrology”. These are the guidelines of the series VDI/VDE 2534: Sheet 1 “Optical 3D measuring systems - Imaging systems with point-by-point probing”, sheet 2 “Optical 3-D measuring systems - Optical systems based on area scanning” , and sheet 3 “Optical 3D-measuring systems - Multiple view systems based on area scanning” which were published between 2008 and 2012.

This ISO/FDIS draft settles for the first time

• the specification of different measurement modes (single view, multiple view),
• the definition of measurement volumes (single view measurement volume, concatenated measurement volume),
• the definition of additional characteristics (e.g. distortion error),
• the application of additional optional characteristics (for probing error testing and bidirectional length measurement error testing),
• the assessment of the structural resolution and
• the assessment of the test value uncertainty for test measurements.

The FDIS draft will be commented in the predefined ISO balloting procedure and will lead to the final ISO 10360-11 standard.