Here is an example of a portable flue gas analyser that is configurable from two sensors to nine sensors. The 2 or 3 gas analysers would be used for boiler maintenance and similar tasks. A 4 gas analyser or 5 gas analyser would generally be intended for EPA compliance testing and jobs of that nature and the more complicated flue gas analysers will be used for laboratory jobs or research into pollution control devices. These portable flue gas analysers are generally built using electrochemical sensors, but infrared flue gas analysers are also in use. This one can be fitted with infrared sensors for some components. Such a portable flue gas analyser is easy to transport, falling into the category of hand baggage for air travel and being light in weight. This type of equipment is probably the mainstay of environmental compliance monitoring.
For some applications it is not enough to just sample the gas. A special sample conditioning system is needed. These are also available in many types. Here is an example of a flue gas analyser with an integrated sample conditioning system allowing accurate measurement of soluble gas components. It is otherwise identical to the instrument shown above and is especially suited to use as an infrared gas analyser since the sample conditioner prevents fogging of the optics. Such a 5 gas analyser (or maybe even more components) may be essential for EPA compliance testing in some cases. The sample conditioner makes long-term measurements of three or more hours, as required in some countries, a simple task. The standard flue gas analyser would gradually "drown" in the condensate produced in this length of time! Also, our experience has shown that measurement of SO2 is roughly 20 % too low when the flue gas analyser is used without sample conditioner.
As can be seen, these are not toys, but professional instruments that will give years of service and deliver results capable of standing up in a court of law. Pollution control equipment is important these days and EPA compliance testing may be the difference between profit and forced closure. The flue gas analyser is no longer so expensive that only huge companies can afford to buy and operate a combustion gas tester.When you add in the possibility of extra profit by so-called CO2 trading as envisaged in the Kyoto Protocol, the reasons sum up in favour of testing. It is not a luxury, it is an essential!