Corrected asymmetry plots

Presenting experimental data as asymmetry plotsA _i (t), rather than as single histogramsN _±i (t), removes the muon lifetime which allows the time dependence of the ensemble muon polarization to be viewed directly (particularly useful for longitudinal and zero field experiments). The combining of two histograms effectively increases the statistical accuracy by a factor of 2. However, differences in efficiency within a pair of counters, differences in solid angle subtended by a pair of counters, counter pairs which are not exactly 180 degrees apart and errors in the random background estimate can distort the calculation of the asymmetry. This paper describes the expected distortions and explains how to correct for them.