The paper is concerned with the measurement of the 2nd-order kernel in a Volterra-series representation of a nonlinear system by continuous or discrete crosscorrelation using an antisymmetric pseudorandom input signal derived from an m sequence. It is shown that the crosscorrelation measurements are related to the corresponding kernel values by a set of equations which may be structured into a number of independent subsets. The m-sequence properties determine how the maximum order of the subsets for off-diagonal values is related to the upper bound of the arguments for nonzero kernel values, which is used as an index of performance. The performance of signals derived from binary, ternary and quinary m sequences is investigated, and the characteristic polynomials and performance indexes of signals with superior performance are tabulated. Comparison of the results obtained demonstrates the advantages of ternary signals in this application, and an example is used to illustrate the solution of a typical problem.