IMPROVEMENTS RELATING TO MEASURING CIGARETTE PRESSURE DROP

摘要

A cigarette making machine is provided with a pressure drop measuring unit (1) located at or close to the garniture of the making machine. The pressure drop of a gas stream of constant volume is introduced into the compacted tobacco rod beneath the format finger (2) on the making machine at a point at which that pressure drop measurement correlates with the bound pressure drop of the finished cigarette. The unbound cigarette pressure drop or draw resistance experienced by the smoker can be calculated using the bound tobacco rod pressure drop obtained by correlation with the measured pressure drop across the rod in an algorithim processed by calculation means. The degree of ventilation of the cigarette may also be utilised in the algorithim calculation. Comparator means allows the unbound cigarette pressure drop to be maintained within pre-set limits by varying cigarette parameters which affect the overall unbound cigarette pressure drop.