危险场所划分 Area classification
根据爆炸环境出现的频率和持续的时间把危险场所划分为不同的区域。
气体场所分为三个区域：0区、1区和2区。
Hazardous areas are classified into zones based upon the frequency of the occurrence and duration of an explosive gas atmosphere.
The gas area is classified into three zones: zone0、zone 1 and zone 2.
0区
Zone 0
爆炸性环境中的爆炸混合物以气体、蒸气或薄雾形式连续出现或长时间存在的场所。
A place in which an explosive atmosphere consisting of a mixture with air of flammable substances in the form of gas, vapour or mist is present continuously or for long periods.
1区
Zone 1
在正常运行时，爆炸性环境中可能出现气体、蒸气或薄雾形式的爆炸性混合物的场所。
1区是防爆电气设备的典型应用场所。
A place in which an explosive atmosphere consisting of a mixture with air of flammable substances in the form of gas, vapour or mist is likely to occur in normal operation occasionally.
2区
Zone 2
在正常运行时，爆炸性环境中不太可能出现气体、蒸气或薄雾形式的爆炸性混合物，如果出现也只是偶尔发生并且短
时间存在的场所。通常情况下，“短时间”是指持续时间不多于2个小时。
A place in which an explosive atmosphere consisting of a mixture with air of flammable substances in the form of gas, vapour or mist is likely to occur in normal operation occasionally but, if it dose occur, will persist for a short period only. As a rule, “for a short period only”means up to 2 hours.
粉尘场所分为三个区域：20区、21区和22区。
The dust area is classified as three zones：zone20、zone 21 and zone 22.
20区
Zone 20
在正常运行过程中可燃性粉尘连续出现或经常出现，其数量足以形成可燃性粉尘与空气混合物和／或可能形成无法控制和极厚的粉尘层的场所及容器内部。
Area in which combustible dust, as a cloud, is present continuously or frequently, during normal operation, in sufficient quantity to be capable of producing an explosive concentration of combustible dust in mixture with air and / or where layers of dust of uncontrollable and excessive thickness can be formed.
21区
Zone 21
在正常运行过程中，可能出现粉尘数量足以形成可燃性粉尘与空气混合物但未划入20区的场所。该区域包括，与充入或排放粉尘直接相邻的场所、出现粉尘层和正常操作情况下可能产生可燃浓度的可燃性粉尘与空气混合物的场所。
Area not classified as zone 20 in which combustible dust, as a cloud, is likely to occur during normal operation, in sufficient quantities to be capable of producing an explosive concentration of combustible dust in mixture with air. This zone can include, among others, areas in the immediate vicinity of powder filling or emtying points and areas where dust layers occur and are likely in normal operation to give rise to an explosive concentration of combustible dust in mixture with air.
22区
Zone 22
在异常条件下，可燃性粉尘云偶尔出现并且只是短时间存在、或可燃性粉尘偶尔出现堆积或可能存在粉尘层并且产生可燃性粉尘空气混合物但未划入21区的场所。如果不能保证排除可燃性粉尘堆积或粉尘层时，则应划分为21区。
Area not classified as zone 21 in which combustible dust clouds may occur infrequently and persist for only a short period, or in which accumulations or layers of combustible dust may be present under abnormal conditions and give rise to combustible mixtures of dust in air. Where, following an abnormal condition, the removal of dust accumulations or layers cannot be assured, then the area is to be classified zone 21.
