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GB12212-90 技术制图焊缝符号的尺寸,比例及简化表示法GB12326-90 电能质量电压允许波动和闪变GB12348～12349-90 工业企业厂界噪声标准及其测量方法
GB12212-90 Technical drawings Weld symbol size, proportion and simplified representation GB12326-90 Power quality voltage fluctuation and flicker allowed GB12348 ~ 12349-90 Industrial enterprises boundary noise standards and measurement methods