Metrological Research and Analysis of Oxygen Transmission Rate Testers

As the main test instrument for measuring the oxygen transmission rate of packaging materials, the accuracy of the measurement results is crucial to the quality safety, effectiveness and stability of the product during the shelf life. The measurement principle and key testing technology of oxygen transmission rate testers are studied and analyzed first, and then research on metrological methodology is carried out. A set of standard film is developed on the innovative “sandwich” design structure which includes three specifications of high, medium and low oxygen transmission rate. The measurement range is below 0.05cm3/(pkg·24 h·0.1 MPa), between (0.10 ~ 0.20) cm3/(pkg·24 h·0.1 MPa) and over 0.25cm3/(pkg·24 h·0.1 MPa) respectively. Moreover, the quantity value of oxygen transmission rate can be traceable to the National Standard and be reusable to improve the measurement repeatability and reproducibility. By metrological evaluation, the relative expanded uncertainty of the standard value is Urel = 6% (k = 2). Besides, the calibration specification for oxygen transmission rate testers has been drafted for the first time in China, and published as JJF 2181 in 2024. In this way a unified calibration method has been established in packaging industry. The experimental results proved that the above achievement can effectively solve the calibration and quality evaluation of oxygen transmission rate testers, and ensure that the measurement results given by this kind of instrument are accurate and reliable. It is helpful to provide metrological guarantee for the formulation of product shelf life and the healthy development of packaging industry.