By making an analysis of the proportionality between the load and the tilt angle of the lever of a balance provided with an elastic fulcrum, it is clarified that the maximum value of deviation from the linearity is raised to about the second power in proportion to the magnitude of this tilt angle.
If the lever is balanced previously with an appropriate moment given to the lever which is caused by the spring rigidity of fulcrum, the maximum deviation becomes about one half of what the usual method has brought about, resulting in the improvement in the proportionality.
These facts have been experimentally confirmed with a balance in which a wire fulcrum is used as the elastic fulcrum.