The cut power method is an empirical correlation used to predict the collection efficiency of a scrubber. In this method, penetration is a function of the cut diameter of the particles to be collected by the scrubber. Recall that the cut diameter is the diameter of the particles collected by the scrubber with at least 50% efficiency. Because scrubbers have limits to the size of particles they can collect, knowledge of the cut diameter is useful in evaluating the scrubbing system (USEPA-84/03, p. 9-11).
In the cut power method, penetration is a function of particle diameter and is given as: