Which Explosion-Proof Level Is Higher, AT1 or BT4

The IIB explosion-proof classification inherently exceeds IIA, and the T4 temperature class provides lower and safer temperatures than T1. Thus, BT4 has a superior explosion-proof rating.

III	C	T 135℃	Db	IP65
III Surface dust		T1 450℃	Ma	IP65
		T2 300℃	Mb
		T3 200℃
	A Flammable flying flocs		Da
		T4 135℃
			Db
	B Non conductive dust	T2 100℃	Dc
	A Conductive dust	T6 85℃

Each explosion-proof class targets specific safety goals. Detailed information can be found by searching on Shenhai Explosion Proof.