Calibration system for cigarette packet sealing degree standards and its uncertainty evaluation

To address the problem of measurement traceability of the cigarette packet sealing degree standard, a calibration system including a mass flow controller, thermometer, and differential pressure gauge was constructed. Cigarette packet sealing degree standards of 1, 2, 3, and 4 kPa were selected to test the repeatability and stability of the calibration system. The sources of uncertainty in the calibration system were analyzed, a mathematical model was established to evaluate the uncertainty of measurement results, and the uncertainty of the system was evaluated. The results showed that: 1) The coefficient of variation of the measurements of the system was around 0.01%, and the relative range of the measurements was less than 0.2%, indicating good repeatability and stability. 2) With the inclusion factor k of 2 and the confidence probability of 95%, the expanded uncertainty of the system was 0.650%, and the main source of measurement uncertainty was from the gas volume flow control system. This system supports the promotion of measurement accuracy of cigarette packet sealing degree testers.