Normalized number of required pulsar events per pulsar period, n_p, to achieve a prescribed signal-to-noise ratio in the histogram, SN_Hist, as a function of measurement time M = P·T for four values of background photon rates n_n. Period T = 33.7 ms and bin width bw = T/ 20 are the same as for Fig. 8. The effective width of the first pulsar peak is taken as d = 3 ms (compare Appendix A). The black circle indicates the case of Fig. 8; i.e., n_p = 0.585, SN_Hist = 0.55, fraction of n_p leading to histogram peak: y = 0.65.