What do the Zones in explosion protection mean?
Gases:
Zone 0 (Category 1): permanent or long-term danger of explosions
Zone 1 (Category 2): hazardous atmosphere occasionally exists
Zone 2 (Category 3): explosive atmosphere exists only rarely, and then only for a short time
Dusts:
Zones 20, 21, 22 with ...
more
Can a 3-wire transmitter also work in a 2-wire configuration?
No.