In order to evaluate the flame-retardant performance of wire cables, iec 60332-1, iec 60332-2 and iec 60332-3 were formulated respectively. Iec60332-1 and iec60332-2 are respectively used to evaluate the flame retardant capability of a single cable when it is laid on an incline and vertically (corresponding to GB12666.3 and GB12666.4 in China). Iec60332-3 (domestic equivalent to gb12666.5-90) is used to evaluate the flame retardant capability of beam cable when it is vertical, compared with that of beam cable when it is vertical.
In November 2008, China decided to invest 4 trillion yuan to tackle the financial crisis
三线制变送器如图三所示，所谓三线制即是电源正端用一根线，信号输出正端用一根线，电源负端和信号负端共用一根线。其供电大多为24V.DC，输出信号有4-20mA.DC，负载电阻为250Ω或许0-10mA.DC，负载电阻为0-1.5KΩ；有的还有mA和mV信号，但负载电阻或输入电阻，因输出电路方式不一样而数值有所不一样。以上三个图中，输入接纳外表的是电流信号，如将电阻RL并联接入时，则接纳的即是电压信号了。
充油电缆充油电缆型号HYAT铠装充油电缆HYAT22HYYT23HYAT23HYAT53充油电缆执行标准：YD/T充油电缆结构特点：HYAT型市内通信电缆采用全色谱绝缘，铝塑综合护套（即电缆的纵包屏蔽铝带与护套粘结成一体，形成密封护层），具有电气性能优越，施工方便的特点。
