An alternate method of measuring material buckling in a subcritical assembly is presented. The fundamental mode of the neutron flux is isolated by using the orthogonality introduced when the equation for the neutron flux is a subcritical assembly is multiplied by [cos πx/a cos πy/b dx dy] and integrated over the cross-sectional area of the assembly. The resulting double integral is evaluated by measuring the neutron flux at grid points and then employing tabular integration. After neutron flux measurements have been taken on two levels, the inverse relaxation length and material buckling can be evaluated. The precision of these determinations are obtained by using the method of propagation of precision indices.