Standard strain gauges are encapsulated in Constantan foil with phenolic-acetal backing and, with self-temperature compensation, are available in a variety of patterns and materials for research and industrial stress measurement. Versions with paper-based acetal backings are also supplied for use in composite materials or cement structures.
Special purpose strain gauges include Karma foil gauges with glass-fibre reinforced polyamide backing which are said to have excellent heat-resistance and insulation characteristics. Within the special purpose range, waterproof and submergible versions are available for use up to 50bar. Special purpose strain gauges also suit applications where high elongation, uneven plastic deformation, high altitude and other challenging environmental factors need to be resolved.
Variohm also supply terminal tabs with a choice of polyimide or glass fibre reinforced backings for use across the ZEMIC strain gauge range.