Alignment Unit

Always exact – with the alignment unit

Reliable and precise test results are possible only if the stress condition achieved in the samples corresponds to the specifications.

To determine material parameters, uniaxial stresses are usually applied- generated by tensile and compressive forces. These forces are determined using calibrated measuring sensors. The calibration of the measurement technology is only part of the necessary check. This is because, if there are misalignments (axial and angular errors) in the power train, an additional bending moment is applied to the samples.

It is precisely this bending moment that is to be eliminated by installing the reference cell during calibration by means of a corresponding structure, but it is physically present later on the sample. In addition, standard force transducers cannot measure this bending moment.

ASTM E 1012, for example, provides a general procedure for determining the bending moment due to axis errors and a classification into accuracy classes. It is described here that using strain gauges (DMS)

the bending strain is to be determined according to height and direction. A calibration rod is usually used for this, which is applied with the corresponding strain gauges.

Intelligent software then determines not only the height and direction of the bending components from the measured strains, but also the type of error, i.e. the subdivision into axial offset and angular error.

With an alignment unit, these axis errors can then be corrected in a targeted manner using adjusting screws. This occurs in-situ while the calibration rod is installed in the load train and is under load.

FORM+TEST has developed and successfully used alignment units with dynamic loads of up to 500 kN for this purpose. In addition, FORM+TEST offers all the necessary accessories for measuring axis errors.

Application area

  • uniaxial static and dynamic test machines

Summary of technical data

  • Sizes 50 – 500 kN
  • durable design
  • flexible adaptation
  • optionally with complete accessories

Options

  • Calibration rod with 8 or 12 strain gauges
  • analysis software with suitable measurement system
Alignment Unit
Alignment Unit Software Screenshot
Alignment Unit