Upgrades are now available to operate the TGA200 with a thermoelectrically cooled (TEC) laser, enabling the TGA200 to no longer require liquid nitrogen refills. Upgrading a TGA200 requires a new TEC laser module, TGA200A Input Module, TGA200A Output Module, and TGA TEC software. Contact Campbell Scientific for more information. The TGA200 Trace-Gas Analyzer measures trace-gas concentration in an air sample using tunable-diode laser absorption spectroscopy (TDLAS). This technique provides high sensitivity, speed, and selectivity. The TGA200 is a rugged, portable instrument designed for use in the field. Common applications include gradient or eddy-covariance flux measurements of methane or nitrous oxide and isotope-ratio measurements of carbon dioxide.