为了研制塑料悬臂梁冲击性能能力验证试样，评价实验室塑料悬臂梁冲击性能检测能力，依据GB/T 1843-2008，ISO 180：2000和CNAS （中国合格评定国家认可委员会）所制定的程序文件实施能力验证计划，采用S_S ≤ 0.3σ准则对试样进行均匀性检验，采用t检验法对试样进行稳定性检验，使用Z比分数法判定实验室的检测结果。结果表明：能力验证试样的均匀性和稳定性均符合要求；对32家实验室的悬臂梁冲击性能能力验证结果的统计显示，结果满意的为29家，结果有问题或不满意的为3家。

To develop proficiency testing samples for determination of Izod impact strength of plastics, and to evaluate the testing ability of laboratories for determination of Izod impact strength of plastics, according to the procedures prescribed in GB/T 1843-2008, ISO 180:2000 and CNAS (China National Accreditation Service for Conformity Assessment), the uniformity tests for samples were carried out on the basis of the guideline of S_S ≤ 0.3σ, and the stability tests for samples were carried out on the basis of the t-test method. The testing results of laboratories were evaluated by the Z-score method. The results show that:the uniformity and stability of proficiency testing samples were in conformity with the requirements; the statistical analysis on proficiency testing of Izod impact strength of 32 laboratories showed that there were 29 laboratories whose results were satisfied and 3 laboratories whose results were suspected or unsatisfied.