Short breaks are generally arranged in one of two ways: (1) a portion of each counting period is set aside for a short break or (2) every other count period is used as a short break. In the first case, counts may be taken for 4 minutes out of every 5-minute counting period (or 13 out of 15, or any other convenient combination). Assuming that the rate of flow during the short break is the same as for the observed portion of the counting period, the total count during each counting period can be estimated as: