BF350 High-precised resistance strain gauge is foil metal strain gauge,widely used in pressure sensor and weighing sensor. It shares features of high accuracy, good stability,fully-closed structure and automatic compensation of temperature and creep. Specifically, its backing material is made of modified phenolic while its gate wire is made of cuni. BF350 is mainly fit for 0.02 level manufacturing crafts pressure sensor which means its output deviation should be controlled within 0.02 so its precision is really high. You could use it to measure the strain of components directly ! How to use? 
(1)Mainly fit for 0.02 level manufacturing crafts pressure sensor which means its output deviation should be controlled within 0.02 so its precision is really high. 
(2)Measure the strain of components directly. 
(3)Choose suitable electric circuit to know how the resistance changes.