NEN 10721-3-7-1994 IEC 721-3-7-1987+A1-1991 环境条件分类.第3部分:环境参数组分类及其严酷程度分级.第7节:便携式和不固定使用的产品
Classification of environmental conditions.Part 3:Classification of groups of environmental parameters and their severities.Section 7:Portable and non-stationary use(IEC 721-3-7:1987+A1:1991)