Long-term measurements of strains with strain-gauges and stability of strain-gauge transducers

Results from experiments aiming at the evaluation of the long-term stability (at ambient temperature and in laboratory conditions) under constant sustained loading of strain-gauges and strain-gauge transducers are reported.

Results from experiments aiming at the evaluation of the long-term stability (at ambient temperature and in laboratory conditions) under constant sustained loading of strain-gauges and strain-gauge transducers are reported. A preliminary series of experiments involved the loading for more than

1 year of two 1 kN transducers, one at 100 % of its nominal force (2 mV/V) and the other at 50 % of its nominal force (1 mV/V).Then followed a detailed investigation of the influence of the strain-gauge type, length, bonding and sign of strain on the long-term strain measurement. Creep curves under load and creep recovery curves after unloading are represented graphically. A large variability in long-term stability, ranging from less than 0.2% to more than 1%, is observed.