压力表压力比绝对压力()大气压力。 ["A、大l个","B、小l个","C、大2个","D、小2个"]
提高形状精度的措施?
合金渗碳钢的含碳量为()。 ["A、l%","B、0.5%~l%","C、0.3%~0.5%","D、0.25%以下"]
CO2气体保护焊的焊接工艺参数有()。 ["焊丝直径","焊接电流","电弧电压","焊接速度","气体流量"]
埋弧自动焊在正常电流密度下焊接时其静特性为() ["平特性区","上升特性区","陡特性区","缓降特性区"]
完整的测量过程包括哪些内容?