All strain gauge types mentioned above are available with different measuring grid lengths:
- 1.5 mm: where space is a constraint or when highly selective measurement results are required
- 3 mm: for inhomogeneous materials and where space is a requirement or not
- 6 mm: for inhomogeneous materials and where space is not a requirement
The right measuring grid length: The measuring grid length depends on the aim of measurement, since the result of a measurement with strain gauges will be determined as the average of strains. In general, measuring grid lengths of 3 to 6 mm generates a better result.
Long measuring grids are recommended where there is an inhomogeneous material such as concrete or wood. A long strain gauge will bridge the inhomogeneity of the work piece and return the strain underneath the measuring grid as the measurement result.
Short measuring grids are suitable for detecting a local strain state. Therefore, they aresuitable for determining strain gradients (strain gauge chains), the maximum point of notch stresses and similar stresses.