But, you already have one
While bench testing a run of stand alone NOx converters I realized how unfair RATA testing can be. The reason I started building this product was because of time spent in the field during testing. I am proud of the equipment I build and the performance record of that equipment in the field. So when a test team rolls in with a trailer full of "cold" equipment, sets up and less than one day later tells me my full time 24/7 equipment that calibrates every day (and passes) is wrong, I kind of have a problem.
Don't get me wrong I have had test teams that are as professional as they come and know every aspect of testing. On the other hand I had test teams that pull up to site towing a horse trailer with equipment bouncing all the way down a dirt road. Then once they set up the equipment, calibrated the analyzers by adjusting the gas bottle regulator until the desired reading was achieved. Trus story
The stand alone NOX converter was developed to run High Temp Conversion as well as Moly. The reason I needed something outside of the analyzer for conversion was that on one trip the test team said my readings were high on NO2. Thier explanation was that my in analyzer converter was experiencing a "back pressure" problem?? So I asked the team what method of conversion were they using and they said they were verifying thier reading with the on site lab (refinery). As it turns out, they were grabbing a sample from the stack in a Tedlar bag and taking it to the lab by walking about a mile on a very sunny, hot day. Needless to say when I questioned the stability of the sample it was met with a reply of "we know what were doing".
Now I use a stand alone as a tie breaker and a lot of my clients do too.
No sense in arguing with "experts".
Bob Daversa/Datatek Systems/[email protected]
Consultant - Retired Field Services Engineer in Emissions Monitoring
5 年I've been questionable of RATA results for years - when it just doesn't make since - ask the RATA field team, (nicely), to run your calibration gas through their analyzer and see how accurate they really are - the results can be "enlightening".....
Northeast and Mid Atlantic Sales Manager, Laser/Process Analyzer Specialist
5 年Very good post.?
VP, Technical for Montrose Air Quality Services, LLC, Stack Emission Testing
5 年Bob, you are right - a RATA done “exactly right” according to the Method still has variables such as the converter efficiency, how dry does each conditioner really get the sample, how much NO2 scrubbing takes place, differences in CO2 quenching between analyzers, etc. Any of these can easily be made worse. It’s almost a wonder that RATA is passed in some situations!
Semi-Retired from Advanced Environmental Compliance, LLC
5 年Interesting.
Environmental Scientist
5 年Thank you for sharing this, Bob. Even identically built units sitting side by side one another rarely operate “identical”, let alone the gambit of sources us stack testers are continuously up against - testing some permanent installations (analytical technologies) vs. our reference has loads of variance.