Gas detection for tunnel June 1st 2009 Over 500 Crowcon detectors have
been chosen for installation
throughout the 28km long
Guadarrama Tunnel in Spain.
Carbon monoxide (CO), nitrous
dioxide (NO2) and oxygen (O2)
levels are measured by intrinsically
safe Xgard detectors (validated to
IEC61508 SIL2/3), while methane
(CH4) levels are detected using
Crowcon's flameproof (Exd) infrared
Nimbus units. Signals from
these detectors are processed by
over 70 Vortex rackmounted
controllers, which are connected to
PLCs via RS485 and provide
operators with all gas readings and
alarm/fault information. If the
detectors register dangerous levels
of gases, ventilation and exhaust
systems are automatically triggered
by the Vortex control panels, which
also pinpoint which detector is in
alarm mode and immediately
transmit this information via PLC
to a SCADA system. More articles from Crowcon Detection Instruments Ltd: |