Errors of circumference measurement caused by the way of rotating

In order to promote the measurement accuracy of circumference of cigarette or filter rod sample with an irregular cross section, the effects of eccentric distance and the ratio between scanning rate and sample rotational speed on diameter measurement were analyzed following the establishment of a rotational model of irregular samples and configuration of a standard meter for circumference measurement, and four circumference meters of different types were compared. The results showed that:1) It was proved that when sample's rotation angle ≤0.04° in a single test run, the variation of diameter reading and absolute ovality was less than 0.001 and 0.05 mm, respectively. 2) Eccentric distance did not influence circumference measurement, but it would bring about the errors of measured maximum and minimum diameters. With reference to the eccentric distance of the four circumference meters, the possible errors of maximum and minimum diameter caused by eccentric distance were assessed, and they all fell within the tolerance range of diameter measurement.