Dust level (the first X)0: no protection1: to prevent large solid intrusion2: to prevent the invasion of solid medium size3: prevent small solid into intrusion4: prevent solid objects greater than the entry of 1mm5: to prevent the accumulation of harmful dust6: completely prevent dust enteringWaterproof grade (second X)0: no protection1: the drops into the shell had no effect2: when the shell is tilted 15 degrees, water droplets drops into the shell had no effect3: water or rain from 60 degrees corner to the housing no effect4: liquid from any direction poured into the shell did not damage effect5: rinse with water without any harm6: can be used for the cabin environment7: in a short time immersion resistant (1m)8: in the long time of soaking under certain pressureShell protection grade (IP code) standards:1) by IEC (INTERNATIONAL ELECTROTECHNICAL COMMISSION) the IEC: International Electrotechnical Commission Standard IEC 529 – 598; 2) GB GB 700 - 86; 3) GB 4208.Shell protection grade (IP code) laboratory:0：没有保护1：防止大的固体侵入2：防止中等大小的固体侵入3：防止小固体进入侵入4：防止物体大于1mm的固体进入5：防止有害的粉尘堆积6：完全防止粉尘进入防水等级(第二个X表示)0：没有保护1：水滴滴入到外壳无影响2：当外壳倾斜到15度时，水滴滴入到外壳无影响3：水或雨水从60度角落到外壳上无影响4：液体由任何方向泼到外壳没有伤害影响5：用水冲洗无任何伤害6：可用于船舱内的环境7：可于短时间内耐浸水（1m）8：于一定压力下长时间浸水外壳防护等级（IP代码）的标准有：1）由IEC（INTERNATIONAL ELECTROTECHNICAL COMMISSION）所起草国际防护和防水试验标准：国际电工委员会标准IEC 529 – 598；2）国标GB 700 – 86；3）GB 4208等。外壳防护等级（IP代码）实验室：