FAQ
Frequently Asked Questions
Procurement and quality questions, answered the way a supplier questionnaire asks them.
Common Questions
If a question below is not covered, it can be answered directly — see the contact page.
How often should a CMM be calibrated?
Most shops verify annually, tied to their quality system's calibration interval and the machine's duty cycle. Heavy weldment inspection work can justify a shorter interval than occasional use warrants.
What is the difference between calibration and verification?
Calibration establishes readings against reference values with a stated uncertainty. Verification checks the machine against a stated specification, such as ISO 10360-2 or ASME B89.4.1. Most work sold as CMM calibration is verification.
What does the ISO 10360-2 length measurement error test actually check?
Five calibrated test lengths are measured three times each in seven positions across the working volume, 105 measurements total. Each deviation is compared against the machine's stated MPE.
Can calibration be done on-site, and how long is the machine down?
Bridge and gantry CMMs are normally verified in place. Time on site depends on working volume and whether adjustment is needed; this is confirmed in the quotation.
What temperature does the room need to be for testing?
ISO 1 sets 20°C as the dimensional reference temperature. Steel expands roughly 11.5 µm per meter per °C, so gradient control matters as much as the absolute setpoint. Artifacts are soaked before testing.
What happens if the machine fails the as-found test?
As-found deviations are recorded before adjustment. Out-of-tolerance results are reported before correction so an impact assessment against the last passing certificate can be run if required.
How do I check that a certificate is accredited for my machine's range?
The laboratory's scope of accreditation is published by its accreditation body and lists the specific ranges and parameters covered. That scope, not the certificate alone, determines what was actually covered.
What is a CMC and why does it matter to my tolerances?
Calibration and measurement capability is the smallest uncertainty a laboratory can claim within its scope. If the CMC does not comfortably support your tolerance, a stated 4:1 test uncertainty ratio may not hold.
Will this satisfy an IATF or AS9100 auditor?
Auditors under IATF 16949 and AS9100 look for evidence that an external laboratory is accredited to ISO/IEC 17025 or otherwise acceptable to the customer, plus complete certificate content and traceability records.
What is an error map, and can it be updated on my controller?
The volumetric error map is a compensation table the controller applies to correct known geometric errors. Whether it can be updated depends on whether the controller is OEM-locked; this is checked before the visit.
Further Detail
Standards, traceability and equipment control are set out on the quality system page. Competence and authorization are covered on the our team page. Commercial terms are in the terms and conditions.
Question about a specific item?
Send the detail and it is answered against the method that would actually be used.