Chemical / Gas Concentrations

Catalytic Sensor

There are many different types of sensors for detection concentration levels of chemicals and gasses. These sensors are critical for safety considerations in many industrial applications.

Following is a table providing a brief summary of sensor types and applications.

 

Sensor type	Detectable gases	Usable range	Pro's	Con's
Electrochemical	Toxics, oxygen	ppm levels	Low power, accurate, repeatable	3 year lifetime slightly lower at high temps; some types are cross-sensitive
Pellistor	Flammables	LEL levels	Generally good in all ways; portable	Can be damaged by high levels of H2S, but poison resistant types are available
Infrared	Flammables and CO2	0.1 (or less) to 100% by volume	Fail safe; generally excellent	Expensive (but getting cheaper); non-portable
Thermal Conductivity	Many, at % levels, including binary mixtures	% levels	20 year life (at least); stable; can detect inert gases	Only appropriate for certain gases