Grim Reaper of tech

Rudy knew he was biding his time. The process gas chromatograph (GC) he specified more than a quarter-century ago was still “tapping its toe,” an expression he liked to use for the analyzer dutifully repeating its endless cycles of sample injection, component separation and analysis. However, now his access to spare parts—PC boards, especially—was close to the eBay phase. In similar death-defying desperation, his friends at the neighboring refinery were sending out ailing door boards—an innovation their favorite supplier sold them in the 1990s to update already aging GCs—to a small enterprise (not their vendor) that could restore them to life. Both teams of professionals knew the day was coming when their strategies would succumb.

When he installed his new NOx analyzers for stack continuous emission monitoring systems (CEMS) more than a dozen years ago, he was impressed how  repurposed and cleverly integrated components utilized the “chemiluminescence” principle to accurately measure nitrogen oxides for U.S. EPA permit compliance. It was an unforeseen stroke of luck that his analyzer choice precisely matched the instruments used by the environmental group’s relative accuracy test audit (RATA) service provider. As practitioners know, the preeminent duty of a CEMS instrument is to pass its yearly RATA as well as daily drift tests.

However, while his aging gas chromatograph was still dutifully—amazingly—tapping its toe, Rudy was stunned to learn that parts for his NOx analyzers would no longer be available after year’s end. Unlike the GC, he couldn’t survive a weeks- or months‑long outage on a CEMS unit. The site’s permits allowed only a brief maintenance window; beyond that, they’d slip out of compliance, incur escalating fines, and earn the wrong kind of attention from corporate leadership. 

A GC failure would certainly be taxing for operations, but they could limp along with periodic lab analyses or inferential readings. For CEMS, there was no such fallback. As the implications sank in, Rudy felt like he was staring down the barrel of a loaded gun. 

The agency officer asked him, “Do you feel lucky?”

What was the gamble? He could stock up on parts while they were still available, and take the chance that he didn’t miss one that turned out to be essential. He would also be tempting fate, betting that his techs and/or his vendor’s shop would remain competent in repairs, a challenge for instruments that were few, and had run for years without needing much more than filter changes and an occasional UV source. His instrument used tiny pressure sensors that looked like they belonged in a medical device. Once, he searched for the part number on the Internet, and discovered it had been superseded by newer generations with incompatible pinouts. As pressure control was a key to maintaining flow ratios for the chemiluminescence method, a scarce spare part would be a serious threat.

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Rudy decided he’d better have the new model installed before some unexpected but serious fault rendered his old analyzer incapable of passing a RATA or daily drift test. However, for the EPA, it’s not that simple. Just because an analyzer is new, factory tested and certified, it hasn’t passed a RATA. This audit is intended to certify the entire system, including sample handling and conditioning. If he could make it to the next test scheduled, which was months away, he could switch to the new instrument at that time.

The surprisingly reliable chemiluminescence method had served him well, but he was intrigued by newer tunable‑diode‑laser (TDL) approaches—particularly the Rosemount Quantum Cascade Laser (QCL) analyzer. His existing sample system was already designed to provide cooled, dehydrated and filtered gas for analysis, which made it harder to justify the higher cost. The greater concern was matching the RATA service provider’s method. “Don’t switch horses in midstream,” he reminded himself. 

The QCL might offer greater precision, but introducing a new measurement technology risked creating discrepancies. It worried him because time was already growing short, and the EPA wouldn’t care how elegant the method was. The agency just wanted the device to pass its test.

Unlike his obvious good fortune with his old GCs, this sudden retirement and obsolescence was a shocking and unwelcome surprise, especially when the enterprise was pressuring his plant manager to be increasingly frugal. The Grim Reaper of tech makes unexpected visits to our world, and despite their dedicated caretakers, analyzers are no exception.