规定了评估天然或加工锰矿石和铬矿石质量变化的实验方法，目的是按照相关国际标准的规定，通过质量基准系统法和两阶段法确定取样程序。它还规定了用质量基准系统法和两阶段法检查取样精度的方法。

Specifies experimental methods for the evaluation of quality variation of manganese and chromium ores, whether natural or processed, for the purpose of defining sampling procedure by the mass-basis systematic method and the two-stage method as specified in the relevant International Standards. It also specifies methods for checking the precision of sampling by the mass-basis systematic method and the two-stage method.