Monitoring NH3 using extractive sampling is difficult. The sample must be kept above 290oC (554oF) to prevent formation of ABS and sulfuric acid, both of which damage the sampling and analytical equipment.
Without direct gas analysis, many parameters will influence the NH3 measurement, including inlet NOx concentration, fuel composition and catalyst performance.
Infrared-based extractive systems may also be affected by signal interferences from gases formed by the process – including sulfur dioxide (SO2) or water (H2O) – and high levels of dust.
A Tunable Diode Laser (TDL) analyzer can be installed directly into the process ducts, providing a signal that is averaged across the duct and giving a more accurate NH3 reading even in uneven flow conditions.
The SERVOTOUGH Laser 3 Plus is…
It also offers market-leading intervals between calibrations and cleaning, so it's ideal in applications where uptime is critical. There are a few different types of SERVOTOUGH Laser 3 Plus models with varying measurement capabilities. Talk to your DMS sales engineer to see which tool is right for your application.