The Model N500 CAPS NOx analyzer uses superior Cavity Attenuated Phase Shift (CAPS) Spectroscopy to measure True NO₂, NOx, and NO gases. The instrument combines direct NO₂ measurements with highly efficient gas phase titration (GPT) to convert and measure the NO gas component. An automatic baseline reference cycle accounts and compensates for any potential baseline drift due to varying environmental conditions. 

​CAPS technology is inherently accurate and sensitive, uses very little power, and requires far less maintenance than Chemiluminescence. The Model N500 raises the bar for NO₂, NOx, and NO measurement accuracy, while simultaneously reducing instrument operation and maintenance costs. 

Instrument functions and controls are managed through a series of integrated microprocessor-controlled modules utilizing a simple and reliable CAN Bus communications architecture. Each module is independently assembled and calibrated allowing easy and fast field replacement to maximize instrument uptime. The long-life sample filter further improves efficiency with a ~6 months exchange interval in ambient air quality monitoring applications.

Intuitive operation and calibration of all N Series products is achieved through the NumaView™ Software interface. The graphical user interface (GUI) is customizable, giving the user fast and efficient access to instrument status, as well as measurement data and diagnostic parameters in either numeric or graphical form. NumaView™ Remote Software (included at no charge) provides the same virtual interface and complete instrument control, as well as access to the instrument’s large internal data storage buffer from a remote PC or tablet​​.