Alignment Measurement

Verifying Test Axis Alignment as per Nadcap

Nadcap stands for "National Aerospace and Defense Contractors Accreditation Program" and was originally a global accreditation program for suppliers to the aerospace and defense industries. Nadcap's goal is to generate economical approaches to special processes and products and promote continual improvement within accredited companies.

In contrast to certification of quality management systems as per ISO 9001 and EN 9100, Nadcap accreditation includes both detailed examination of special technical processes and an audit with regard to the observance of defined specifications and guidelines. Aerospace industry manufacturers and suppliers in particular define extremely demanding requirements for the technical and staff qualifications of testing laboratories. These requirements are specified in standards, directives, and audit criteria, and are checked through Nadcap audits allowing maximum process stability to be attained and standardization of quality guaranteed.

Alignment measurement is a component of Nadcap accreditation and is based on ASTM E1012, which stipulates compliance with defined tolerances.This is reflected in Nadcap-defined audit criteria AC 7101 and AC 7122, which define the conditions for the measuring procedure, that is the verification of test axis alignment.In addition to aerospace manufacturers and service providers, an increasing number of companies in other sectors are affected by alignment measurement as part of Nadcap accreditation requirements, for example in the mechanical and plant engineering industry and in the metals industry.

Alignment Measurement to ASTM E1012

The standardized option for alignment measurement is described in ASTM E1012 and includes a recorded inspection of test axis alignment. The electronic measurement of bending influences that can arise as a result of the smallest angular errors or offset in the test axis is required.

Erroneous Alignments of Test Axes (Misalignments) Cause Non-Uniform Force Application to the Specimen. This Leads to an Increased Risk of Breakage Near the Clamping.

Misalignments can be especially common with brittle materials. Stiff and brittle materials break with seeming low tensile stress and strain in the area of the largest bending. This is where ZwickRoell's alignment services come into play: a highly developed procedure enables visualization of the specific bending strain with the help of strain gages and reporting to initiate required measures for alignment.

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Angular alignment errors

View of non-uniform force application to the specimen through angular offset
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Concentric alignment errors

View of non-uniform force application to the specimen through axial offset

Our Services

Based on ASTM E1012, strain-gaged alignment transducers, which preferably conform to the geometry of the specimen to be tested at a later time, are required. An experienced ZwickRoell service technician positions the strain-gaged alignment transducer in the test axis of your testing system and it is then loaded in the elastic range.

In the event of non-uniform force application to the specimen, the applied strain gages will register different strains. These are digitalized through a connected electrical measurement amplifier and transferred to a special testXpert II software test program. Material properties are determined and logged in testXpert II according to standard specifications and specimen geometries. A simple, structured evaluation in testXpert II enables a ZwickRoell service technician to identify errors in the test axis on the basis of characteristic measurement results. If necessary, measures can be taken using components specifically developed for alignments to resolve alignment errors. In addition, testXpert II provides adjustment recommendations for the alignment unit option, allowing detected alignment to be corrected easily and conveniently.

Our standardized strain-gaged alignment transducer works with a large percentage of the materials testing machines to be tested. Furthermore, defined geometry data can be used with strain-gaged alignment transducer according to your specific requirements.

ZwickRoell standardized strain-gaged alignment transducers for alignment measurements fulfill Nadcap and ASTM E1012 requirements. Read more about ZwickRoell strain-gaged alignment transducers...

Alignment Measurement
Standard	ASTM E1012	ASTM E1012	ASTM E1012	ASTM E1012
Method	Nadcap AC 7101 For metals	Nadcap AC 7101 Metals	Nadcap AC 7101 Metals	Nadcap AC 7122 Composites
Design	Round strain-gaged alignment transducer	Round strain-gaged alignment transducer	Round strain-gaged alignment transducer	Flat strain-gaged alignment transducer
Nominal force of the machine	Max. 50 kN	Max. 100 kN	Max. 250 kN	All
Application	12 times	12 times	12 times	12 times
Number of measuring planes	3	3	3	3
Strain gages per plane	4	4	4	4
F_max of the strain-gaged alignment transducer	20 kN	40 kN	100 kN	17.5 kN
Standard measuring points	10%/20%/40% F_max - 5 kN/10 kN/20 kN	10%/20%/40% F_max - 10 kN/20 kN/40 kN	10%/20%/40% F_max - 25 kN/50 kN/100 kN	1,000 μm/m Determined strain approx. 17.5 kN
Protective elements	Necessity depends on grips used	Necessity depends on grips used	Necessity depends on grips used	Required
Gripping dimensions without protective elements	L: 262 mm M16 thread	L: 262 mm M16 thread	L: 398 mm M24 thread
Gripping dimensions with protective elements	L: 334 mm Ø 28 mm	L: 334 mm Ø 28 mm	L: 443 mm Ø 35 mm	L: 254 mm B: 10.2 mm

ZwickRoell benefits

By using standardized strain-gaged alignment transducers, ZwickRoell guarantees a high degree of comparability with customer-specific specimen dimensions (adaptation).
Individual geometry data can be converted used with the strain-gaged alignment transducer
Alignment measurement as part of inspection and calibration is possible, which means no additional travel costs are incurred
Alignment measurement is quick thanks to ZwickRoell's standard-compliant strain-gaged alignment transducers
Convenient testXpert II software with adjustment diagrams directly display the individual components of the alignment error and adjustment instructions for the operator
Continuous graphic and numerical display of test results of bending and percentage bending
Predefined test sequences consist of zero-measurement, measurement clamped without axial strain, measurement under load, zero-measurement repetition, measurements at a 0°/90°/180°/270° transducer mounting position, and top-down measurements
Precise measurement results via measurement of inverted positioning
Complete, detailed recording of measurement results as required by the standards and beyond (incorporation of images possible)
Factory test report stating mechanical and electrical characteristics of the ZwickRoell strain-gaged alignment transducer
Complete integration of the HBM measurement amplifier in the testXpert II testing software
everything from a single source, from advice to implementation
correction of alignment errors by adjustment using the optionally available alignment unit
Alignment measurement is also possible on machines from other manufacturers
Qualified ZwickRoell experts guarantee professional and individualized support for questions and individual requirements.

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