Statistical effects in longevity measurements on bubble memories

A distribution function is presented in closed form which describes the statistical errors expected in longevity slope measurements made on the data loops of a bubble memory. Plots of this function are provided for several common experimental cases. The standard deviation of the distribution function is used to establish how experimental parameters should be selected to minimize statistical error. Limiting cases are examined. Averaging and the problems associated with fitting curves to longevity data points are briefly discussed.