Beyond Compliance

Industrial gas analyzers are often viewed through a regulatory lens: instruments installed at the stack to demonstrate that emissions remain within permitted limits. The GM32 challenges that convention.

While the GM32 is a reliable and fully capable emissions monitoring system, its real value extends beyond compliance. By providing rapid, direct measurement of gas concentrations, it can serve as a real-time indicator of process performance and of process problems as they develop.

The fundamental difference is where and how the measurement occurs. The GM32 uses Differential Optical Absorption Spectroscopy (DOAS) to measure gases in situ, directly within the process gas stream. Depending on configuration, it can simultaneously measure NO, NO₂, NH₃ and SO₂, together with process temperature and pressure. There is no need to extract a sample and transport it through long heated lines to a remote analyzer cabinet.

For NO and NO₂ measurement in heat recovery steam generators (HRSG), the cross-duct version over the entire HRSG duct can be used as the active measuring path enabling measurement of very low concentrations of pollutants. With response times from approximately five seconds of the cross-duct configuration, the GM32 can provide operators and control systems with information while there is still time to act.

Consider selective catalytic reduction (SCR). Effective control requires balancing NOx reduction against ammonia consumption and NH₃ slip. Too little reagent compromises NOx removal; too much wastes chemicals and can contribute to downstream operating problems. Measuring NO and NH₃ close to the process provides timely feedback that can be used to optimize reagent injection rather than simply report the final emissions result. The in-situ GM32 proves again it can be a process optimization sensor.

Building on the GM31

The GM32 did not introduce in-situ measurement from scratch. Its predecessor, the GM31, already employed DOAS and offered simultaneous measurement of gases including SO₂, NO and NH₃. The GM32 is better understood as the evolution of a proven measurement principle into a more capable, maintainable and process-focused platform.

Multiple independently scaled measuring ranges allow one analyzer to accommodate both low emissions concentrations and higher process-control ranges. Automatic self-testing provides ongoing confidence in measurement performance without routine test-gas intervention, while its modular architecture simplifies servicing and helps reduce maintenance effort.

These improvements are important because an optimization sensor must deliver more than analytical accuracy. It must provide fast, dependable and actionable information.

The GPP Advantage

A key part of the GM32 platform is its choice of probe technologies. In addition to the open-path GMP probe, the GM32 can be equipped with the GPP gas-permeable probe, extending in-situ measurement into challenging, high-dust applications.

Rather than exposing an open optical measurement path directly to the process, the GPP uses a gas-permeable filter element. Process gas diffuses through the filter into a protected optical path, while dust remains outside. UV light passes through this measurement volume and is reflected through the gas to the analyzer. This approach is particularly valuable in dusty processes, where contamination of the optical path can otherwise compromise measurement availability. Automatic probe heating also helps prevent condensation on optical surfaces, supporting reliable operation under difficult process conditions.

Importantly, the GPP is also gas-testable. Test gas can be introduced directly into the probe, allowing analyzer response to be checked or adjusted while the probe remains installed in the duct. It combines the immediacy of in-situ measurement with a practical means of validating analyzer performance.

The GM31 established a strong foundation for direct in-situ gas analysis. The GM32 builds on that foundation with improved serviceability, measurement flexibility and process-control capability.

For more information on the GM31 upgrade promotion please reach out to sales@intrepid-group.ca.