Polypropylene (PP), as a common automotive plastic, enhances the performance of parts, but emits odorous volatile compounds and increases the risk of exposure to air pollutants. The organic compounds and carbonyl compounds emitted can induce respiratory diseases and even cancers. However, the measurement of odor intensity is regarded as a challenge for the vehicle market in order to meet the increasingly strict environment regulations. This study aimed to numerically express the odor intensity of volatile compounds from automotive polypropylene. The samples with different odor intensities were prepared by the thermostatic heater, and the electronic nose composed of ten various sensors was employed to acquire the odor information. The factor analysis was implemented to analyze the odor data of different intensities. The results showed that the odor intensity values of four materials were around 1.3 at 50℃, which increased to 1.8, 2.0, 2.3, and 1.9 respectively at 80℃. Besides, grey relation analysis was introduced to verify the results of numerical expression, and the corresponding relation degree in accord with the odor intensity value. This study shows the numerical expression could be used as an effective alternative to rapidly and objectively describe the odor intensity in vehicles.

聚丙烯（PP）作为一种常见的汽车塑料，可以提高零件的性能，但会散发出有气味的挥发性化合物，并增加了暴露于空气污染物的风险。排放的有机化合物和羰基化合物可诱发呼吸系统疾病，甚至引发癌症。然而，为了满足日益严格的环境法规，气味强度的测量被认为是车辆市场的挑战。这项研究旨在用数字表达汽车聚丙烯中挥发性化合物的气味强度。用恒温加热器制备气味强度不同的样品，并采用由十个不同传感器组成的电子鼻获取气味信息。进行因子分析以分析不同强度的气味数据。结果表明，四种材料的气味强度值在50℃时约为1.3，在80℃时分别增至1.8、2.0、2.3和1.9。此外，还引入了灰色关联度分析对数值结果进行验证，并根据气味强度值确定了相应的关联度。这项研究表明，该数值表达式可以用作快速，客观地描述车辆气味强度的有效替代方法。