型：采用工程塑料压制而成，具有较强的防腐和防水性能，适用于增安型外壳中作引入装置用。

Type I: Made of engineering plastic, corrosion-proof and water-proof, it is used as leading device in safety-increased shell.

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整体为复合型结构，外壳采用增安型结构，具有较强的防水、防尘能力，内装按钮、指示灯、电流表均为防爆元件。

Compound structure of safety - increased type, with functions of water - proofing, dust-proofing inside is arranged button, indicator, Ammeter of explosion-proof types.

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