The invention presented in this work creates the possibility of a portable
gun--revolver, pistol, carbine, riffle or hand-machine gun, to recognize
its owner, in progressive levels of handling safety. Three levels of
handling safety are established based on the evaluation of the grip force
or its effect through material deformation or strain gage measurement.
The first level of handling safety does not allow persons with grip force
bellow a given limit, to shoot with a gun. The second level of handling
safety enables the portable gun to recognize an individual as belonging
to a smaller group than the first level. Now, the gun will only recognize
for a successful firing an individual whose grip force, measured by one
strain gage, fit into a small operational range, established and stored
at the moment of acquisition by the owner. The third level of handling
safety enables a portable gun to recognize an individual, as belonging to
an even smaller group than in the second level. In practice this group is
unitary and is composed by the person that grasped the handle to
establish the average local grip forces, measured by six strain gages, at
the acquisition moment.