Alignment Fixtures

Exact axial alignment of the test axis of the materials testing system is a basic requirement for determining accurate characteristic values.

Alignment must be performed very carefully, particularly when testing brittle materials such as fiber composites or certain metals.

Alignment fixture for alignment measurement

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Advantages and features
Exact alignment measurement
Mounting the alignment fixture
Verifying the test axis alignment
Technical overview
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Product information: Alignment fixtures, Fmax 50 kN to 250 kN

Key Advantages and Features

Significant reduction in time and effort required for adjustment
Convenient adjustment, even under tensile or compression load
Ample adjustment range
Angular and axial errors can be corrected independently of each other
Secure gripping of the alignment fixture for long-term retention of any adjustments
Can be attached to top, moving or base crossheads.
A version with flanged interface is available for force level 250kN, enabling a shorter test arrangement and even greater stiffness.

Exact Alignment Measurement

Function description

The alignment fixture is used to accurately compensate for angular and offset errors in the test arrangement. It is an alignment element that is mounted between the testing system's crosshead and the specimen grip or test tool. The adjustment screws are used first to adjust the angular error and then the axis offset. In this way it is possible to adjust each error individually and by means of the configuration. The screw configuration for making adjustments in the X and Y direction makes it possible to correct errors in their respective working direction.

Alignment measurement

Precise guidelines regarding maximum permissible transverse loads are established in the respective application standards.
To verify machine accuracy, adjustment must take place in a loaded state using optionally available strain-gaged alignment specimens, measurement amplifiers, and testXpert III testing software. The calculation routines comply with ASTM E1012.
Purely mechanical adjustment in an unloaded state can be performed via the mounting studs or via a divided specimen clamped in the specimen grips.

Mounting the Alignment Fixture

Alignment fixture in flange connection mounted between the load cell and the specimen grip (image on left)
Alignment fixture with bolt connection mounted directly on the crosshead (image on right)

Learn more about our alignment measurement services

Alignment Measurement—Verifying Test Axis Alignment

Technical Overview

Item no.	058005	058006	068902
Version	50 kN bolts	250 kN bolts	250 kN flange
In conjunction with	AllroundLine and symmetrical specimen grips	AllroundLine and symmetrical specimen grips	AllroundLine and symmetrical specimen grips
Test load, max. (Fmax)	50	250	250	kN
Connection	Bolts Ø36	Bolt Ø60	Flange connection	mm
Load types (symmetric force application)	Tensile/compression/alternating load (static)	Tensile/compression/alternating load (static)	Tensile/compression/alternating load (static)
Permissible bending moment on the mounting stud/flange, max.	1	7.5	30	kNm
Crosshead interface	Centering D70, 8 x M8 on a pitch circle of 115	Centering D70, 8 x M16 on a pitch circle 220	Centering D70, 8 x M16 on a pitch circle 220^[1], 8 x M16 on a pitch circle of 264
Specimen grip interface	Bolt D 36g6	Bolt D 60g6	Centering D70, 8 x M16 on a pitch circle 220
Offset adjustment	± 3	±3	±3	mm
Attainable accuracy with offset adjustment	± 0.01	±0.01	±0.01
angular correction	± 1	±0.7	±0.35	°
Attainable accuracy with angle correction	± 0.006	±0.004	±0.002	°
Dimensions:
Overall height	152	211	145	mm
Installation space height	111	138	142	mm
Diameter	180	250	290	mm
Weight, approx.	14	34	49	kg
Ambient temperature	+10 to +35	+10 to +35	+10 to +35	°C

with intermediate flange (optional unit in BPos)