The 7900-112 kit is the original reduced flow rate kit. It provides different intake and outlet flow rates, and therefore is unsuitable for closed-loop applications. To use this kit, you must install it, select the software setting, and then start the instrument. This kit is supported by firmware version 2.0.25 and newer.

The 7900-113 kit is a replacement for the older 7900-112 kit. The new kit provides the same inlet and outlet flow rate, and therefore is suitable for closed-loop applications. The new kit is supported by firmware version 2.4 and newer. The flow rate with the 7900-113 is around 70 sccm.

Yes. Be sure to select the flow configuration, and then restart the instrument after installing the kit. If the kit has been removed, restore the default flow configuration and restart the instrument.

The LI-7810, LI-7815, and LI-7820 both may issue a series of messages as the instrument warms up and passes through various warm up tests. It may display this message during this time. The message (and all warnings) should be resolved within 30 to 60 minutes after powering up. It may take a little longer under some circumstance. If the error persists after restarting and allowing the instrument to run for 60 to 90 minutes, contact LI-COR or your sales representative.

Your LI-7815 will include either 9978-193 or 9978-234 filters. 9978-193 filters were included with early instruments. 9978-234 are included with later instruments. Either filter is suitable, however, 9978-234 provides additional protection against water being drawn into the inlet.

• Use one (1) of the 9978-193 filters.
• Use two (2) of the 9978-234 filters.

The LI-7815 is a closed path instrument designed for field and bench-top measurements. It provides very precise CO₂ measurements using Off-axis cavity enhanced absorption spectroscopy measurements (OF-CEAS). Other CO₂/H₂O gas analyzers use non-dispersive infrared measurements (NDIR). Although it has higher precision CO₂ measurements than most other LI-COR CO₂ gas analyzers, at one measurement per second, the LI-7815 does not measure quickly enough for most eddy covariance applications.