On frequency and efficiency measurements in counting experiments

The methods for the evaluation of the uncertainties in the frequency and the efficiency in counting experiments are re-examined. It is shown that the confidence intervals, obtained from inverting test acceptance regions with pivotal variables and including the Continuity Correction (CC), give in many cases intervals with coverage and width comparable to those of some more sophisticated methods in use. The Poisson counting with and without background (known or measured) and with acceptance effects, as well as the efficiency determination through binomial counting are considered in detail. Most of the proposed formulae are simple and could substitute the standard textbook ones used by the physicists in their daily practice.