Please help with the explosion prevention issue

Intrinsic safety for explosion prevention is related to explosive gases; it refers to whether the energy released in the event of a device failure can ignite and cause an explosion of those explosive gases under normal atmospheric conditions. . . For these Zone 0, Zone 1, and whatever other zones, are there also specified lower concentration limits for explosive gases? Could it be the case of being fully filled with explosive gases? . . . I don’t understand this either; I’ve never seen any descriptions on this topic. Dust explosions – I don’t know what the mechanism is...... I’m just here to reply to this post. .

Refer to GB50058 and check the explosion-proof mark on the transmitter; it should be fine.

Explosion-proof instruments with dust intrinsically safe (iD type) are available. Generally speaking, gas intrinsically safe systems cannot be used for dust. However, if the various indicators are considered, it can be shown that most intrinsically safe and flameproof instruments are capable of meeting the requirements of dusty environments. The two main differences between dust explosion prevention and gas explosion prevention are: 1. For dust explosion prevention, it is necessary to demonstrate the effect of light focusing and energy on igniting the dust ； (Most instruments don’t have this problem) ； 2. For dust explosion prevention, it is necessary to demonstrate the impact of dust accumulation on surface temperature. (The surface temperatures permitted for dust explosion protection are relatively high, whereas the surface temperatures of most intrinsically safe and flameproof instruments can be kept relatively low.)

I have another question for the teachers: can an ex nadIIbt4 explosion-proof grade instrument share the same instrument junction box as an intrinsically safe instrument? Are separate junction boxes required for NA and D-type meters? Are there any regulatory requirements for this in national standards?