Dear Verisurf customer,
Often we get asked does Verisurf Software satisfy the Product Acceptance Software (PAS) requirements of Boeing D6-51991 Rev N Section 3.1.3 and 3.1.4?
The answer is Yes. Verisurf does have objective evidence of independent PAS certification and can be found here, PTB Certification Verisurf 2021. Verisurf also includes a dataset provided by an independent source (NIST), which has been embedded into Verisurf and is used to test and validate feature construction and output accuracy.
How does Verisurf Perform Product Acceptance Software (PAS) testing?
NOTE: Verisurf is a PAS and is considered a commercial off-the-shelf software used in the acceptance of tooling and parts.
1. Embedded NIST Test Tech-Tip
a. The NIST test contains a total of 240 datasets representing the following feature types per ASME B89.4.10-2000 standard, Methods for Performance Evaluation of Coordinate Measuring System Software. Below is a quick summary of the requirements per feature to be evaluated per the Instructions for using the NIST Reference Pairs
· LINES: X, Y, Z, I, J, K
· PLANES: X, Y, Z, I, J, K
· CIRCLES 2D: X, Y, Z, I, J, K, DIAMETER
· CIRCLES 3D: X, Y, Z, I, J, K, DIAMETER
· SPHERE: X, Y, Z, DIAMETER
· CYLINDER: X, Y, Z, I, J, K, DIAMETER
· CONES: X, Y, Z, I, J, K, DISTANCE, ANGLE
NOTE: GD&T controls such as form, orientation, and location are a result of the feature construction from each dataset and therefore not included in the NIST Reference Pairs.
2. Independent Certification/Accreditation
a. Objective evidence or certification/accreditation (independent) of the PAS from the software developer per ASME B894.10 or equivalent.
· Equivalent: Physikalisch-Technische Bundesanstalt (PTB), an internationally recognized Metrology Institute based in Germany, conducts algorithm testing using the Gaussian theory method of least squares to assess Verisurf’s ability to accurately measure and construct lines, planes, circles, spheres, cylinders, and cones. PTB Certification Verisurf 2021
NOTE: All deviations of the algorithms under test were below the maximum permissible errors (MPE) for all quality characteristics. Characteristic variable Unit MPE Orientation µrad 0.10 Location µm 0.10 Size µm 0.10 Angle µrad 0.10.
3. Sample PAS Work Instruction
3.2 Product Acceptance Software Validation (PAS) and Software Configuration Control
3.2.1 All PCMS software solutions will be validated, and the configuration controlled in compliance with D6-51991. The applicable software configurations shall be controlled by this software validation process, which provides approval of the Portable Coordinate Measurement System (PCMS) software solution and will be performed when a revision has been made to the PCMS software or workstation (computer). The following methods may perform PAS validation.
3.2.1.1 The preferred method of PAS validation is objective evidence of certification independent of the PAS developer and or publisher.
3.2.1.2 Alternative method (A) of PAS validation is using an electronic artifact embedded in the PAS.
3.2.1.3 Alternate method (B) of PAS validation is performed using the CMS to measure a combination of 2D and 3D features on a physical artifact with known values established by the PAS or CMS, which has successfully passed the PAS validation using the preferred or alternative method (A).
3.2.1.4 The maximum allowed deviation is 0.00005”. The PAS validation report for alternative methods (A) and (B) will contain the software revision and deviation shown at eight decimals places and retained on the applicable workstation.
3.2.1.5 If a discrepancy was found during the validation process, the report will reflect the issue, and the PAS developer and or publisher will be notified.
Additional Credits NIST Least Squares Algorithm Test
Need Help?
Please don’t hesitate to contact us if you encounter any problems installing, licensing, configuring, or using any portion of the Verisurf solution.
• Support Email: support@verisurf.com
• Toll-free technical telephone support: (888)713-7201