Abstract: A lightweight accelerometer in a casing or housing, having a very small base member to mechanically contact a surface, vibrations of which are to be determined; a piezoelectric element connected to the base, a seismic mass connected to the piezoelectric element, at least one thin circular diaphragm peripherically fixed to the housing, and with the base, the piezoelectric element, and the seismic mass fixed on, and axially symmetric to, the center of diaphragm and a soft pad member on the housing providing support on and dynamically isolating the housing from the vibrating surface. Several embodiments are disclosed and in each embodiment vibrations are directly transmitted from the vibrating body or surface to the piezoelectric element through the base, a very small half of a steel sphere.

Abstract: A method for the manufacture of a force transducer consisting of a base carrying a stud which carries a set of shear sensitive elements, each having a seismic or force transmitting mass attached to it, the masses being fixed to shear sensitive elements fixed to the stud by means of a cylindrical spring clip surrounding the force transmitting masses and supplying elastic force through the elements to be fixed to the stud, the method involving cutting of slots which are parallel to the axis of the rod with a depth greater than the height of the shear sensitive elements, insertion of shear sensitive elements into the slots, pressing of a cylindrical spring clip around the slotted part of the rod, and cutting radially into the rod so as to remove the material making up the bottom of said slots.