Comparison of Gas Detection Sensors

One of the first challenges for choosing a gas detecting product is to determine which gas sensor technology you need. Gas detection sensor technologies have differing functionality and their limitations depend on the conditions they're exposed to.

Understanding the properties of gas detecting sensors will boost your product selection decision. Choosing the right sensor type for gas monitoring involves an assessment of many factors: Atmospheric Conditions, Environmental Conditions (Temperature/Humidity), Oxygen Content, Poisons and Interferences.

Sensor Type Catalytic Electrochemical Point IR Open Path PID Semiconductor Paper Tape
Works in inert atmosphere No (requires presence of Oxygen) No (requires presence of Oxygen) Yes Yes Yes No (requires presence of Oxygen) No (requires presence of Oxygen)
Resistant to poison Susceptible to poisons like Lead and Sulphur containing compounds, silicones vapours and phosphates Yes Yes Yes Yes Susceptible to poisons like Halide compounds, Silicone vapours, caustic and acid liquids and concentrated vapours Yes
Detects Hydrogen Yes Yes No No No No No
Performance in 100% humidity Yes Yes Yes Yes No Yes No
Performance in typical pressure conditions Yes Yes Yes Yes Yes Yes Yes
Performs in all temperatures Yes No (some sensors can be unstable in low and high temperatures) Yes Yes Yes No, some sensors can be compromised below -40C and above 90C No, some sensors can be compromised below -40C and above 90C
Immune to dust/dirt Yes, with adequate weather and dust protection Yes, with adequate weather and dust protection Yes, with adequate weather and dust protection Yes, with adequate weather and dust protection Yes, with adequate weather and dust protection Yes, with adequate weather and dust protection Yes, with adequate weather and dust protection
Immune to sunlight Yes Yes Yes Yes Yes Yes No (decays tape)
Performance in O2 enriched atmosphere Yes No (can alter readings and response) Yes Yes Yes No (can alter readings and response) No (detection of mineral acids is compromised in Oxygen enriched atmospheres)
Immune to human interference No No No No, e.g. poor alignment No No No
Speed of response <20 secs <30 secs (typical) <6.5 secs <3-5 secs <5 secs <60 secs <10-30 secs
Maintenance requirement High High Low Low High High High

For more, in-depth analysis, read our Gas Detection Sensor Selection guide