Though end users expect at least 3-4 years of installed service life from their catalytic gas detector, the actual lifespan can be much shorter depending upon the installation conditions.
Typical factors causing signal loss/ premature failure of catalytic gas sensors:
- Clogging of the flame arrestor chamber by airborne dirt and oil
- Water submersion or direct impingement into the sensing chamber
- Continuous exposure to background combustible gases
- Inadequate or excessive sensor power
- Prolonged exposure to low oxygen/anaerobic environments
- Loss of sensitivity (poisoning) due to exposure to external substances
Poisoning caused by continuous exposure to various compounds in the environment can damage a catalytic detector when the vapours irreversibly tie up the adsorption sites on the active element, erode the element’s catalytic coating, or cover the element with an impervious coating.
The level of damage sustained by the catalytic detector depends on the type of contaminant, the concentration level, and the length of exposure.
Contaminants known to poison catalytic gas detectors include silicone oils, greases and resins, halogens (chlorine, bromine, fluorine, iodine, halon and freon), tetra- and trichloroethylene, dichlorobenzene, vinyl chloride monomer and PVC vapours, hydrochloric acid, phosphate esters, silanes, phosphorus and gasoline antiknock compounds.
The typical 12-month warranty offered by manufacturers on catalytic detectors does not cover damage to the sensor caused by exposure to known contaminants.
Simrad IR gas detectors from ProDetec are not affected by any of these limitations and are available with an unmatched 15-year warranty on the IR sources.