Fixed Gas Detector Features
- "Always On". May be connected to plant wide communication (DCS/SCADA) for early response.
- No Batteries. Power supply is usually wired and often powered via UPS systems (can be solar powered with battery for remote sites).
- Usually one detector is used for a single gas or gas type (e.g. combustible or chloride);multiple gas hazards usually require multiple gas detectors.
- Calibration is much less frequent than with portable units.
- Only one detector my be necessary in the area of hazardous gas (more units may be required depending on the size of the area, the possible failure mechanisms that could release gas, the gas(es) of interest, etc.)
- Detectors may be located in hazardous areas prior to a worker entering the area. Or detectors may be mounted in areas usually inaccessible to employees.
- A fixed detector has the ability to implement alarms or mitigating actions through discrete or common relays, either locally or plant wide.
- A fixed monitor is useful for detecting combustible gases since it can operate continuously near potential leak sources and the potential ignition sources. A portable unit may not be in the right position or not present when a combustible gas leak occurs.
- Fixed units are also useful in checking for upset conditions releasing toxic gases thus allowing immediate corrective action. With a portable sensor a leak condition could persist indefinitely until an operator arrived in the area wearing the detector.