Sample Conditioning Unit
for Low NOx & Low SO2 Measurements
The accurate emissions monitoring of soluble gases, present in flue gas from industrial and commercial processes, requires a sampling system designed to prevent significant loses of the SO2 and/or NO2 gases in the sampling lines prior to entering the analyzer or measuring device.
Conventional Continuous Emissions Monitoring Systems (CEMS), used to report emissions to the local and federal regulatory agencies, require very sophisticated sampling techniques to achieve this goal. These CEMS sampling techniques are very expensive and impractical when used with portable hand- held analyzers designed to trouble shoot a process.
When using a handheld unit for monitoring NO2 and/or SO2 ranges below 50 ppm, the operator should use an analyzer with a sampling system designed to minimize or eliminate the residence time of the soluble gases in contact with condensing water droplets forming along the walls of the sampling lines. Otherwise, the measured readings could be in excess of 20% lower than the actual values in the process.
E Instruments has designed a Sample Conditioning Unit mounted right at the sampling probe exit before the sampling hose, where the water can rapidly condense and separate immediately from the gas therefore minimizing any contact of the target gases with the liquid water. An additional, water trap commonly used with portable devices is then used to eliminate any water mist remaining in the gas as a protection for the sensors used in the analyzers.
This SCU method allows operators interested to measure low ranges of NO2 and SO2, even down to levels below 10 ppm, to achieve a high level of accuracy in their spot and short-term measurements using one of the E Instruments portable gas analyzers. This Sampling system is currently available for our models E4500, E5500 and E8500 PLUS portable Emissions Analyzers.