Insensitive to all other atmospheric gases, the High-Accuracy CO₂ Analyzer measures carbon dioxide in ambient air with unprecedented accuracy and precision (total measurement uncertainty of less than 1 part in 2000). All without the need for regular external calibration. The instrument can store data practically indefinitely on its internal hard disk drive and can send real-time data to a data logger through its analog, digital (RS232), and Ethernet outputs allowing unattended long-term standalone operation.
Based on high-resolution direct-absorption spectroscopy (see lgrinc.com, Theory Section), the instrument offers negligible zero and span drift and a significantly reduced need for regular calibration with expensive reference gases (compared with conventional instruments). The High-Accuracy CO₂ Analyzer is designed for applications that require the performance of a reference laboratory without the need for regular calibration with expensive gas standards.

The analyzer uses LGR’s patented Off-axis ICOS technology, the fourth-generation cavity enhanced absorption technique, which employs a high-finesse optical cavity as the measurement cell. LGR’s technology has many proven advantages over conventional first-generation cavity ringdown spectroscopy (CRDS) techniques. In brief, since the laser beam does not have to be resonantly coupled to the measurement cell (i.e. precise beam alignment is not critical), LGR Analyzers are relatively inexpensive, simple to build, and inherently robust thermally and mechanically.  In addition, since LGR’s technology can record reliable absorption spectra over a far wider range of optical depths (absorbance values) compared with CRDS, LGR Analyzers provide measurements over a much wider range of mixing ratios (gas concentrations). Finally, due to the ease and simplicity of recording and quantifying the measured spectra using LGR’s Off-Axis ICOS, LGR Analyzers display the entire absorption spectra to the user in real time allowing for immediate system diagnostics and performance validation.