IR29 i Transmitters - Safe monitoring of LEL. If flammable gases and vapors need to be monitored in Ex zone 0, the intrinsically safe IR29 i transmitter is a reliable and robust solution. The IR29 i transmits measured values and status displays in analog (4-20 mA). It is connected via a safety barrier (SB1, SB1 D or Zener barrier) to prevent the ignition of power lines within the Ex zone. In combination with GfG's proven controllers, installation in new gas detection systems as well as retrofitting in existing systems is possible.