Kurš sprādziendrošības līmenis ir augstāks - BT4 vai BT6

According to national standards for electrical explosion protection, both BT4 and BT6 fall under Class IIB.

Elektroiekārtu temperatūras grupa	Maksimāli pieļaujamā elektroiekārtu virsmas temperatūra (℃)	Gāzes/ tvaika aizdegšanās temperatūra (℃)	Piemērojamie ierīces temperatūras līmeņi
T1	450	＞450	T1~T6
T2	300	＞300	T2~T6
T3	200	＞200	T3~T6
T4	135	＞135	T4~T6
T5	100	＞100	T5~T6
T6	85	＞85	T6

However, the ‘T’ classification pertains to the temperature rating of explosion-proof electrical devices. Devices classified as T6 must maintain a surface temperature no higher than 85°C, T5 must not exceed 100°C, and T4 must not surpass 135°C.

The lower a device’s maximum surface temperatūra, the less likely it is to ignite atmospheric gases, thereby enhancing safety. Consequently, the explosion-proof rating of BT6 exceeds that of BT4.