Firstly, all three devices are designed for dust explosion protection and fall under the category of secondary explosion-proof equipment. The explosion-proof ratings are as follows: AT < BT < CT.
| Domaine d'utilisation | Classification des gaz | Gaz de référence | Énergie minimale de l'étincelle d'allumage |
|---|---|---|---|
| Sous la mine | I | Le méthane | 0,280 mJ |
| Usines situées en dehors de la mine | IIA | Propane | 0,180 mJ |
| IIB | Éthylène | 0,060 mJ | |
| IIC | Hydrogène | 0,019 mJ |
CT devices feature a superior dust-proof rating and may be utilized in areas designated for AT and BT. However, AT and BT devices are not suitable for areas that require CT standards.
In other words, CT devices can substitute for AT and BT, but AT and BT devices cannot substitute for CT.
