Need for Intelligent Non-Dispersive Multigas Detection Infrared Sensors for Explosive Environment Operations
A gas sensor detects the presence of different gases in its proximity, and is used as a part of safety system to warn and sound alarm about gases that can have harmful and hazardous effects on humans, animals and environment. The gas detectors are used to detect combustible, toxic, potentially hazardous gases along with oxygen, CO2 and many other gases.
The techniques developed for multigas detection are basically categorized into two types:
- Non-interactive gas analysis
- Interactive gas analysis.
The non-interactive technique is further sub-categorized into two types; non-dispersive infrared (NDIR) and dispersive infrared (DIR) technique.
The NDIR technique offer a number of advantages which include fast detection response, gas detection specificity, long term measurement stability, reduced maintenance cost and good sensitivity.
NDIR are widely used in industries like:
- Wood gasification
- Chemical industries
- Food & beverage industry
- Metal and steel production
- Oil rigs
- Mineral and coal mines
- Indoor complex and residential area.
Some of the major manufacturers of non-dispersive multigas sensors:
- Dexter research centre
- FLIR systems
- General Monitors
- Crowcon Detection Instruments
- Oldham gas and many others
Awite (Germany) recently introduced in the market an in-house developed NDIR sensor ”InfraFRED” and it can detect CH4, CO2, CO, NH3 and many other gases.
One important feature for NDIR sensors that has been overlooked is the intrinsic safety of operating NDIR gas sensors in an explosive environment. The infrared light source in an NDIR gas sensor could ignite a flammable gas inside the sensor. If the ignition escapes from the NDIR sensor, a wider explosion could occur. With technology improvement providing an intrinsically safe, portable NDIR sensor, it may open new application areas, such as underground tunnels and sewers, chemical plants and oil refineries.