3-Element Rectangular Rosette Strain Gauge (375UR).

In this iNote Darryl introduces a new 3-element rectangular rosette strain gauge: CEA-XX-375UR-350.

As a rule, if there is uncertainty about the principal directions, a three-element rectangular rosette is preferable.

A strain gage rosette is, by definition, an arrangement of two or more closely positioned gage grids, separately oriented to measure the normal strains along different directions in the underlying surface of the test part. Rosettes are designed to perform a very practical and important function in experimental stress analysis. It can be shown that for the not-uncommon case of the general biaxial stress state, with the principal directions unknown, three independent strain measurements (in different directions) are required to determine the principal strains and stresses. And even when the principal directions are known in advance, two independent strain measurements are needed to obtain the principal strains and stresses.

[malgailany]

This clears some of the ambiguity for relative newcomers to this field, like me. In some cases when I ordered strain gauges either from MM shop or Digikey, my choices were not optimal for the application because of the large variety in part numbers that make it difficult to choose the proper gauge for the application.

Even with the online, documentation, decoding the part number is sometimes confusing.
Thanks.