Zeiss Coordinate Measuring Machine for High-Precision Measurement
A deviation of a few hundredths of a millimetre in the concentricity of a valve seat compromises the tightness of the assembly before the part even reaches installation. That margin is what justifies pairing large-dimension machining with a dimensional control process held to the same standard as the manufacturing process itself. At its plant in Beasain, ARRI operates a Zeiss coordinate measuring machine integrated into this control flow, applied systematically to parts with complex geometries.
Industrial Metrology: The Measurement Principle
A coordinate measuring machine (CMM) obtains the real geometry of a part through a probing system, either tactile or continuous scanning, which records X, Y and Z coordinates across thousands of points on the surface. Metrology software fits this point cloud to the CAD model or to the drawing dimensions through a best-fit alignment, and from there extracts the actual deviations of each geometric element.
Not all coordinate measuring machines handle this task equally well when the part is large in volume and weight. Portable articulated arms lose volumetric accuracy beyond certain reach distances, whereas a bridge-type CMM mounted on a rigid bed maintains stable measurement uncertainty across its full range. This is decisive when verifying valve bodies with multiple reference features, threads and internal machining in a single setup.
The Zeiss Coordinate Measuring Machine at ARRI
The Zeiss coordinate measuring machine at ARRI extends the plant's dimensional control capability beyond conventional gauges and measuring equipment. Its measuring range allows parts to be verified with an accuracy that manual methods cannot guarantee, particularly in geometries with multiple reference features, threads, flanges or internal machining.
This equipment is integrated into ARRI's standard workflow, certified to ISO 9001 since 2010, as an additional dimensional control tool applied to every production batch. It does not replace visual inspection or measurement with instruments such as micrometres; it complements them, providing objective, traceable data on the actual dimensions of the part.
Dimensional Tolerances and Positional Tolerances
One of the principal values of a coordinate measuring machine is its ability to verify not only linear measurements but also positional tolerances: concentricity between axes, parallelism between faces, perpendicularity of bores or flatness of surfaces. In parts such as large-dimension valve bodies, these positional tolerances are as critical as dimensional tolerances of diameter or length, since the correct assembly and final tightness of the unit depend on them.
A minimal deviation in the concentricity of a valve seat, for example, can result in leaks or premature wear once the part enters service. Three-dimensional measurement makes it possible to detect these deviations before the part leaves the plant, avoiding the cost of non-conformities in later phases of the project.
Dimensional Control and Non-Destructive Testing: A Complementary Process
Dimensional control by coordinate measuring machine forms part of a wider verification process. For parts destined for demanding sectors such as oil and gas, nuclear, cryogenic or hydrogen, ARRI combines this measurement with non-destructive testing, such as dye penetrant inspection, to confirm both geometry and the absence of surface defects in the material.
This combination is particularly relevant in the machining of valve components, where ensuring quality must be an indispensable value of the manufacturing process. Verifying geometry with a coordinate measuring machine prior to dispatch reduces the risk of non-conformities on receipt by the client and reinforces the traceability required in large-scale industrial projects.
One More Capability Within ARRI's Quality Process
The Zeiss coordinate measuring machine is one of the tools with which ARRI backs its commitment to precision in every machining project. Alongside the rest of its industrial metrology equipment and the non-destructive testing available on site, it allows ARRI to offer clients a dimensional guarantee consistent with the complexity of the parts it manufactures.
If you require information on the dimensional control applied to your machining project, please consult ARRI's technical team..
