MTS 709 Alignment System - Manual (Page 76)

709 Alignment System Specimen 76
Channel Calculation
This selection determines which set of gages are used to calculate the applied
load and the axial strain. The Middle Gauges are typically used for 12-channel
specimens. The other settings can be used when fewer channels are available, all
12 channels are not functioning properly, or for diagnostic purposes. For
example, if an 8-channel specimen is used (a specimen with only the upper and
lower gauges attached), typically the Ave Upper + Lower selection would be
chosen. Another example, Middle Only can be selected when the specimen does
not have upper nor lower gauges. Not having upper and lower gauges prevents
the calculation of concentric misalignment. The specimen can be used to validate
angular misalignment (as in MTS’s interpretation of Mil Std 1312 B appendix
C0).
Cross Section Type
This selection determines the type of specimen being used for specimen
alignment. The thick specimen has gauges on all four sides similar to the round
4x90
° specimen. The thin specimen has gauges on the front and back surfaces.
The round 3x120 ° specimen has gauges equally spaced about the circumference.
Parameter Units
This selection defines the units type used on the Specimen tab.