The KFF series foil strain gages have one each sensing element on
both the upper and lower sides of the thick plastic base.
Thus, if a gage cannot be bonded directly to the inside of the
measuring object as in the case of measuring stress due to internal
pressure in high-pressure vessels or stress measurement in box
structures such as bridge girders, the KFF series gages
can be bonded to the surface to obtain strain at the rear.