CO Monitoring with Dilution CEMS

When calibrating two ranges (dual range), perform a multipoint calibration in lieu of a single point calibration to ensure the best linearity performance.  To do this, calibrate to several different points, such as a high point, a low point and a mid point.  The Thermo Scientific™ Model 48i CO Analyzer uses an internally stored calibration curve to accurately linearize the instrument.  Follow step by step directions.

Best engineering practice for removing CO from dilution air is to use a palladium catalyst, which converts CO in the instrument air into CO₂ before using it as the dilution air. How do you ensure the palladium catalyst is performing properly? Make a comparison of three different responses of the Thermo Scientific Model 48i CO Analyzer: 1.) Send bottled Nitrogen directly into the analyzer and record the result. 2.) Send bottled Nitrogen up to the dilution probe and use it as a zero gas and record the result, 3.) Send clean, palladium-scrubbed air directly to the analyzer and bypass the dilution probe.

If different results are obtained between these 3 tests, use this data to aid in troubleshooting

In order to ensure the most accurate measurements of CO, consider installing a filter wheel purge option.  The filter wheel purge option is a housing that surrounds the gas filter correlation wheel (GFC) that is intended to have clean, CO-free air plumbed into it.  This configuration eliminates ambient levels of CO between the wheel and IR detector.  Every new instrument can be purchased with a filter wheel purge option.  On previously purchased instruments, submit a Return Authorization form and send the instrument to our Factory Depot. 

Most people are already performing automatic daily zero and span checks, but not many realize they can also perform automatic calibrations to save time.  Data loggers and/or PLC systems can be easily configured to perform automatic daily zero and span calibrations to adjust the instrument itself.  In addition to saving operator time, automating daily checks on the Thermo Scientific Model 48i CO Analyzer is beneficial when ranges are approaching the LDL of the instrument.  

Today’s gas analyzers, including the Thermo Scientific Model 48i CO Analyzer, are equipped to do much more than simply reporting concentration values.  A great deal of data pertaining to system pressure, flow, temperature and more can be pulled for trending and graphing, allowing for predictive troubleshooting.  Going digital also means the elimination of manual calibration of each analog channel and the added functionality of remote diagnostic capabilities.  

Next Month's Topic: C-Series Gas Analyzer Discontinuation Information