发布时间:2025-01-31 02:29:48
【答案】:B
水准仪按其精度高低可分为DS05、DS1、DS3和DS10等4个等级(D、S分别为“大地测量”和“水准仪”的汉语拼音的第一个字母;数字05、1、3、10表示该仪器的标称精度,是指用该仪器进行水准测量时,往返测1km髙差中误差,其单位是mm)
直缝埋弧焊钢管pehg20553iaej085thk100mm表示什么意思
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