6　Silo Accessory Devices

6.1　Level Metre

6.1.1　For occasions where alarm frequency is high or minimum ignition energy of hybrid mixture in silo is less than 30mJ，level detection and alarm sensor extended into the silo shall be of anti-static type.

6.1.2　The sensor extending vertically into the silo from the silo top，of which the electrode shape and size shall be of non-generating spark discharge type，or be protected on surface with non-sparking discharge material.

6.1.3　Sensors（including the protection plate above the sensors）which extend horizontally or inclinedly into the silo，when their radial dimension extended into the silo are greater than 100mm，they shall comply with Article 5.0.6 of this Code.