Pellistor

A pellistor is a solid-state device [ [http://www.rsc.org/delivery/_ArticleLinking/DisplayArticleForFree.cfm?doi=AD9761300108&JournalCode=AD Pellistor RSC] ] used to detect gases which are either combustible or which have a significant difference in thermal conductivity to that of air. The word "pellistor" is a combination of pellet and resistor.

Principle

The detecting element consist of small "pellets" of catalyst loaded ceramic whose resistance changes in the presence of gas.

History

The pellistor was developed in the early 1960's for use in mining operations as the successor of the flame safety lamp and the canary.

Types

Catalytic

The catalytic pellistor as used in the catalytic bead sensor works by burning the target gas; the heat generated producing a change in the resistance of thedetecting element of the sensor proportional to the gas concentration.

Thermal Conductivity

The thermal conductivity (TC) pellistor works by measuring the change in heat loss (and hence temperature/resistance) of the detecting element in thepresence of the target gas.

References

External links

* [http://www.crowcon.com/talking_gas_pellistor_systems.htm Pellistor]